diff --git a/Tests/test_image_access.py b/Tests/test_image_access.py
index bb30b462d2f..4e3435cfeec 100644
--- a/Tests/test_image_access.py
+++ b/Tests/test_image_access.py
@@ -282,7 +282,7 @@ def test_embeddable(self) -> None:
             home = sys.prefix.replace("\\", "\\\\")
             fh.write(
                 f"""
-#include "Python.h"
+#include <Python.h>
 
 int main(int argc, char* argv[])
 {{
diff --git a/setup.py b/setup.py
index a85731db936..afe4738b501 100644
--- a/setup.py
+++ b/setup.py
@@ -347,7 +347,6 @@ def __iter__(self) -> Iterator[str]:
             ("disable-platform-guessing", None, "Disable platform guessing"),
             ("debug", None, "Debug logging"),
         ]
-        + [("add-imaging-libs=", None, "Add libs to _imaging build")]
     )
 
     @staticmethod
@@ -358,7 +357,6 @@ def initialize_options(self) -> None:
         self.disable_platform_guessing = self.check_configuration(
             "platform-guessing", "disable"
         )
-        self.add_imaging_libs = ""
         build_ext.initialize_options(self)
         for x in self.feature:
             setattr(self, f"disable_{x}", self.check_configuration(x, "disable"))
@@ -855,7 +853,6 @@ def build_extensions(self) -> None:
         # core library
 
         libs: list[str | bool | None] = []
-        libs.extend(self.add_imaging_libs.split())
         defs: list[tuple[str, str | None]] = []
         if feature.get("tiff"):
             libs.append(feature.get("tiff"))
diff --git a/src/PIL/ImageTk.py b/src/PIL/ImageTk.py
index bf29fdba54c..b095b589cb8 100644
--- a/src/PIL/ImageTk.py
+++ b/src/PIL/ImageTk.py
@@ -181,7 +181,7 @@ def paste(self, im: Image.Image) -> None:
         image = im.im
         if not image.isblock() or im.mode != self.__mode:
             block = Image.core.new_block(self.__mode, im.size)
-            image.convert2(block, image)  # convert directly between buffers
+            image.convert2(block)  # convert directly between buffers
             ptr = block.ptr
 
         _pyimagingtkcall("PyImagingPhoto", self.__photo, ptr)
diff --git a/src/Tk/tkImaging.c b/src/Tk/tkImaging.c
index a36c3e0bdc4..0234d2c78f9 100644
--- a/src/Tk/tkImaging.c
+++ b/src/Tk/tkImaging.c
@@ -243,13 +243,9 @@ _dfunc(HMODULE lib_handle, const char *func_name) {
      * Set Python exception if we can't find `func_name` in `lib_handle`.
      * Returns function pointer or NULL if not present.
      */
-
-    char message[100];
-
     FARPROC func = GetProcAddress(lib_handle, func_name);
     if (func == NULL) {
-        sprintf(message, "Cannot load function %s", func_name);
-        PyErr_SetString(PyExc_RuntimeError, message);
+        PyErr_Format(PyExc_RuntimeError, "Cannot load function %s", func_name);
     }
     return func;
 }
diff --git a/src/_imaging.c b/src/_imaging.c
index 5d6d97bedab..ea533f94833 100644
--- a/src/_imaging.c
+++ b/src/_imaging.c
@@ -71,29 +71,20 @@
  * See the README file for information on usage and redistribution.
  */
 
-#define PY_SSIZE_T_CLEAN
-#include "Python.h"
-
 #ifdef HAVE_LIBJPEG
-#include "jconfig.h"
+#include <jconfig.h>
 #endif
 
 #ifdef HAVE_LIBZ
-#include "zlib.h"
+#include <zlib.h>
 #endif
 
 #ifdef HAVE_LIBTIFF
-#ifndef _TIFFIO_
 #include <tiffio.h>
 #endif
-#endif
 
 #include "libImaging/Imaging.h"
 
-#define _USE_MATH_DEFINES
-#include <math.h>
-#include <stddef.h>
-
 #undef VERBOSE
 
 #define B16(p, i) ((((int)p[(i)]) << 8) + p[(i) + 1])
@@ -101,7 +92,7 @@
 #define S16(v) ((v) < 32768 ? (v) : ((v) - 65536))
 
 /* -------------------------------------------------------------------- */
-/* OBJECT ADMINISTRATION                        */
+/* OBJECT ADMINISTRATION                                                */
 /* -------------------------------------------------------------------- */
 
 typedef struct {
@@ -207,22 +198,6 @@ ImagingSectionLeave(ImagingSectionCookie *cookie) {
     PyEval_RestoreThread((PyThreadState *)*cookie);
 }
 
-/* -------------------------------------------------------------------- */
-/* BUFFER HANDLING                                                      */
-/* -------------------------------------------------------------------- */
-/* Python compatibility API */
-
-int
-PyImaging_CheckBuffer(PyObject *buffer) {
-    return PyObject_CheckBuffer(buffer);
-}
-
-int
-PyImaging_GetBuffer(PyObject *buffer, Py_buffer *view) {
-    /* must call check_buffer first! */
-    return PyObject_GetBuffer(buffer, view, PyBUF_SIMPLE);
-}
-
 /* -------------------------------------------------------------------- */
 /* EXCEPTION REROUTING                                                  */
 /* -------------------------------------------------------------------- */
@@ -244,12 +219,6 @@ static const char *no_palette = "image has no palette";
 static const char *readonly = "image is readonly";
 /* static const char* no_content = "image has no content"; */
 
-void *
-ImagingError_OSError(void) {
-    PyErr_SetString(PyExc_OSError, "error when accessing file");
-    return NULL;
-}
-
 void *
 ImagingError_MemoryError(void) {
     return PyErr_NoMemory();
@@ -275,13 +244,8 @@ ImagingError_ValueError(const char *message) {
     return NULL;
 }
 
-void
-ImagingError_Clear(void) {
-    PyErr_Clear();
-}
-
 /* -------------------------------------------------------------------- */
-/* HELPERS                                */
+/* HELPERS                                                              */
 /* -------------------------------------------------------------------- */
 
 static int
@@ -466,8 +430,7 @@ getpixel(Imaging im, ImagingAccess access, int x, int y) {
     }
 
     /* unknown type */
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static char *
@@ -631,7 +594,7 @@ getink(PyObject *color, Imaging im, char *ink) {
 }
 
 /* -------------------------------------------------------------------- */
-/* FACTORIES                                */
+/* FACTORIES                                                            */
 /* -------------------------------------------------------------------- */
 
 static PyObject *
@@ -714,7 +677,7 @@ _radial_gradient(PyObject *self, PyObject *args) {
 }
 
 static PyObject *
-_alpha_composite(ImagingObject *self, PyObject *args) {
+_alpha_composite(PyObject *self, PyObject *args) {
     ImagingObject *imagep1;
     ImagingObject *imagep2;
 
@@ -728,7 +691,7 @@ _alpha_composite(ImagingObject *self, PyObject *args) {
 }
 
 static PyObject *
-_blend(ImagingObject *self, PyObject *args) {
+_blend(PyObject *self, PyObject *args) {
     ImagingObject *imagep1;
     ImagingObject *imagep2;
     double alpha;
@@ -922,17 +885,12 @@ _convert(ImagingObject *self, PyObject *args) {
     int dither = 0;
     ImagingObject *paletteimage = NULL;
 
-    if (!PyArg_ParseTuple(args, "s|iO", &mode, &dither, &paletteimage)) {
+    if (!PyArg_ParseTuple(
+            args, "s|iO!", &mode, &dither, &Imaging_Type, &paletteimage
+        )) {
         return NULL;
     }
     if (paletteimage != NULL) {
-        if (!PyImaging_Check(paletteimage)) {
-            PyObject_Print((PyObject *)paletteimage, stderr, 0);
-            PyErr_SetString(
-                PyExc_ValueError, "palette argument must be image with mode 'P'"
-            );
-            return NULL;
-        }
         if (paletteimage->image->palette == NULL) {
             PyErr_SetString(PyExc_ValueError, "null palette");
             return NULL;
@@ -946,20 +904,16 @@ _convert(ImagingObject *self, PyObject *args) {
 
 static PyObject *
 _convert2(ImagingObject *self, PyObject *args) {
-    ImagingObject *imagep1;
-    ImagingObject *imagep2;
-    if (!PyArg_ParseTuple(
-            args, "O!O!", &Imaging_Type, &imagep1, &Imaging_Type, &imagep2
-        )) {
+    ImagingObject *imagep;
+    if (!PyArg_ParseTuple(args, "O!", &Imaging_Type, &imagep)) {
         return NULL;
     }
 
-    if (!ImagingConvert2(imagep1->image, imagep2->image)) {
+    if (!ImagingConvert2(imagep->image, self->image)) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -1207,8 +1161,7 @@ _getpixel(ImagingObject *self, PyObject *args) {
     }
 
     if (self->access == NULL) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     return getpixel(self->image, self->access, x, y);
@@ -1410,8 +1363,7 @@ _paste(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -1571,7 +1523,6 @@ _putdata(ImagingObject *self, PyObject *args) {
         } else {
             seq = PySequence_Fast(data, must_be_sequence);
             if (!seq) {
-                PyErr_SetString(PyExc_TypeError, must_be_sequence);
                 return NULL;
             }
             double value;
@@ -1630,7 +1581,6 @@ _putdata(ImagingObject *self, PyObject *args) {
         /* 32-bit images */
         seq = PySequence_Fast(data, must_be_sequence);
         if (!seq) {
-            PyErr_SetString(PyExc_TypeError, must_be_sequence);
             return NULL;
         }
         switch (image->type) {
@@ -1684,8 +1634,7 @@ _putdata(ImagingObject *self, PyObject *args) {
 
     Py_XDECREF(seq);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -1745,8 +1694,7 @@ _putpalette(ImagingObject *self, PyObject *args) {
     self->image->palette->size = palettesize * 8 / bits;
     unpack(self->image->palette->palette, palette, self->image->palette->size);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -1770,8 +1718,7 @@ _putpalettealpha(ImagingObject *self, PyObject *args) {
     strcpy(self->image->palette->mode, "RGBA");
     self->image->palette->palette[index * 4 + 3] = (UINT8)alpha;
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -1798,8 +1745,7 @@ _putpalettealphas(ImagingObject *self, PyObject *args) {
         self->image->palette->palette[i * 4 + 3] = (UINT8)values[i];
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -1835,8 +1781,7 @@ _putpixel(ImagingObject *self, PyObject *args) {
         self->access->put_pixel(im, x, y, ink);
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -2003,8 +1948,7 @@ im_setmode(ImagingObject *self, PyObject *args) {
     }
     self->access = ImagingAccessNew(im);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -2067,8 +2011,7 @@ _transform(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -2195,8 +2138,7 @@ _getbbox(ImagingObject *self, PyObject *args) {
     }
 
     if (!ImagingGetBBox(self->image, bbox, alpha_only)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     return Py_BuildValue("iiii", bbox[0], bbox[1], bbox[2], bbox[3]);
@@ -2276,8 +2218,7 @@ _getextrema(ImagingObject *self) {
         }
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -2340,8 +2281,7 @@ _fillband(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -2356,8 +2296,7 @@ _putband(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -2943,8 +2882,7 @@ _draw_arc(ImagingDrawObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -2981,8 +2919,7 @@ _draw_bitmap(ImagingDrawObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -3038,8 +2975,7 @@ _draw_chord(ImagingDrawObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -3093,8 +3029,7 @@ _draw_ellipse(ImagingDrawObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -3157,8 +3092,7 @@ _draw_lines(ImagingDrawObject *self, PyObject *args) {
 
     free(xy);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -3189,8 +3123,7 @@ _draw_points(ImagingDrawObject *self, PyObject *args) {
 
     free(xy);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 /* from outline.c */
@@ -3218,8 +3151,7 @@ _draw_outline(ImagingDrawObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -3275,8 +3207,7 @@ _draw_pieslice(ImagingDrawObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -3327,8 +3258,7 @@ _draw_polygon(ImagingDrawObject *self, PyObject *args) {
 
     free(ixy);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -3382,8 +3312,7 @@ _draw_rectangle(ImagingDrawObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static struct PyMethodDef _draw_methods[] = {
@@ -3537,7 +3466,7 @@ _effect_spread(ImagingObject *self, PyObject *args) {
 }
 
 /* -------------------------------------------------------------------- */
-/* UTILITIES                                */
+/* UTILITIES                                                            */
 /* -------------------------------------------------------------------- */
 
 static PyObject *
@@ -3573,7 +3502,7 @@ _getcodecstatus(PyObject *self, PyObject *args) {
 }
 
 /* -------------------------------------------------------------------- */
-/* DEBUGGING HELPERS                            */
+/* DEBUGGING HELPERS                                                    */
 /* -------------------------------------------------------------------- */
 
 static PyObject *
@@ -3588,8 +3517,7 @@ _save_ppm(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 /* -------------------------------------------------------------------- */
@@ -3977,8 +3905,7 @@ _reset_stats(PyObject *self, PyObject *args) {
     arena->stats_freed_blocks = 0;
     MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -4038,8 +3965,7 @@ _set_alignment(PyObject *self, PyObject *args) {
     ImagingDefaultArena.alignment = alignment;
     MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -4063,8 +3989,7 @@ _set_block_size(PyObject *self, PyObject *args) {
     ImagingDefaultArena.block_size = block_size;
     MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -4092,8 +4017,7 @@ _set_blocks_max(PyObject *self, PyObject *args) {
         return ImagingError_MemoryError();
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -4108,8 +4032,7 @@ _clear_cache(PyObject *self, PyObject *args) {
     ImagingMemoryClearCache(&ImagingDefaultArena, i);
     MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 /* -------------------------------------------------------------------- */
@@ -4197,19 +4120,19 @@ extern PyObject *
 PyImaging_GrabScreenX11(PyObject *self, PyObject *args);
 #endif
 
-/* Experimental path stuff (in path.c) */
+/* Path object (in path.c) */
 extern PyObject *
 PyPath_Create(ImagingObject *self, PyObject *args);
 
-/* Experimental outline stuff (in outline.c) */
+/* Outline object (in outline.c) */
 extern PyObject *
 PyOutline_Create(ImagingObject *self, PyObject *args);
 
+/* MapBuffer implementation (in map.c) */
 extern PyObject *
 PyImaging_MapBuffer(PyObject *self, PyObject *args);
 
 static PyMethodDef functions[] = {
-
     /* Object factories */
     {"alpha_composite", (PyCFunction)_alpha_composite, METH_VARARGS},
     {"blend", (PyCFunction)_blend, METH_VARARGS},
@@ -4218,9 +4141,6 @@ static PyMethodDef functions[] = {
     {"new_block", (PyCFunction)_new_block, METH_VARARGS},
     {"merge", (PyCFunction)_merge, METH_VARARGS},
 
-    /* Functions */
-    {"convert", (PyCFunction)_convert2, METH_VARARGS},
-
     /* Codecs */
     {"bcn_decoder", (PyCFunction)PyImaging_BcnDecoderNew, METH_VARARGS},
     {"bit_decoder", (PyCFunction)PyImaging_BitDecoderNew, METH_VARARGS},
diff --git a/src/_imagingcms.c b/src/_imagingcms.c
index 1805ebde17f..e1cf627c3d5 100644
--- a/src/_imagingcms.c
+++ b/src/_imagingcms.c
@@ -26,15 +26,11 @@ kevin@cazabon.com\n\
 https://www.cazabon.com\n\
 "
 
-#define PY_SSIZE_T_CLEAN
-#include "Python.h"  // Include before wchar.h so _GNU_SOURCE is set
-#include "wchar.h"
-#include "datetime.h"
+#include "libImaging/Imaging.h"  // Set _GNU_SOURCE in Python.h before wchar.h
 
-#include "lcms2.h"
-#include "libImaging/Imaging.h"
-
-#define PYCMSVERSION "1.0.0 pil"
+#include <wchar.h>
+#include <datetime.h>
+#include <lcms2.h>
 
 /* version history */
 
@@ -620,12 +616,6 @@ cms_profile_is_intent_supported(CmsProfileObject *self, PyObject *args) {
 
 #ifdef _WIN32
 
-#ifdef _WIN64
-#define F_HANDLE "K"
-#else
-#define F_HANDLE "k"
-#endif
-
 static PyObject *
 cms_get_display_profile_win32(PyObject *self, PyObject *args) {
     char filename[MAX_PATH];
@@ -654,8 +644,7 @@ cms_get_display_profile_win32(PyObject *self, PyObject *args) {
         return PyUnicode_FromStringAndSize(filename, filename_size - 1);
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 #endif
 
@@ -672,20 +661,17 @@ _profile_read_mlu(CmsProfileObject *self, cmsTagSignature info) {
     wchar_t *buf;
 
     if (!cmsIsTag(self->profile, info)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     mlu = cmsReadTag(self->profile, info);
     if (!mlu) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     len = cmsMLUgetWide(mlu, lc, cc, NULL, 0);
     if (len == 0) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     buf = malloc(len);
@@ -723,14 +709,12 @@ _profile_read_signature(CmsProfileObject *self, cmsTagSignature info) {
     unsigned int *sig;
 
     if (!cmsIsTag(self->profile, info)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     sig = (unsigned int *)cmsReadTag(self->profile, info);
     if (!sig) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     return _profile_read_int_as_string(*sig);
@@ -780,14 +764,12 @@ _profile_read_ciexyz(CmsProfileObject *self, cmsTagSignature info, int multi) {
     cmsCIEXYZ *XYZ;
 
     if (!cmsIsTag(self->profile, info)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     XYZ = (cmsCIEXYZ *)cmsReadTag(self->profile, info);
     if (!XYZ) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
     if (multi) {
         return _xyz3_py(XYZ);
@@ -801,14 +783,12 @@ _profile_read_ciexyy_triple(CmsProfileObject *self, cmsTagSignature info) {
     cmsCIExyYTRIPLE *triple;
 
     if (!cmsIsTag(self->profile, info)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     triple = (cmsCIExyYTRIPLE *)cmsReadTag(self->profile, info);
     if (!triple) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     /* Note: lcms does all the heavy lifting and error checking (nr of
@@ -835,21 +815,18 @@ _profile_read_named_color_list(CmsProfileObject *self, cmsTagSignature info) {
     PyObject *result;
 
     if (!cmsIsTag(self->profile, info)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     ncl = (cmsNAMEDCOLORLIST *)cmsReadTag(self->profile, info);
     if (ncl == NULL) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     n = cmsNamedColorCount(ncl);
     result = PyList_New(n);
     if (!result) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     for (i = 0; i < n; i++) {
@@ -858,8 +835,7 @@ _profile_read_named_color_list(CmsProfileObject *self, cmsTagSignature info) {
         str = PyUnicode_FromString(name);
         if (str == NULL) {
             Py_DECREF(result);
-            Py_INCREF(Py_None);
-            return Py_None;
+            Py_RETURN_NONE;
         }
         PyList_SET_ITEM(result, i, str);
     }
@@ -926,8 +902,7 @@ _is_intent_supported(CmsProfileObject *self, int clut) {
 
     result = PyDict_New();
     if (result == NULL) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     n = cmsGetSupportedIntents(INTENTS, intent_ids, intent_descs);
@@ -957,8 +932,7 @@ _is_intent_supported(CmsProfileObject *self, int clut) {
             Py_XDECREF(id);
             Py_XDECREF(entry);
             Py_XDECREF(result);
-            Py_INCREF(Py_None);
-            return Py_None;
+            Py_RETURN_NONE;
         }
         PyDict_SetItem(result, id, entry);
         Py_DECREF(id);
@@ -1042,8 +1016,7 @@ cms_profile_getattr_creation_date(CmsProfileObject *self, void *closure) {
 
     result = cmsGetHeaderCreationDateTime(self->profile, &ct);
     if (!result) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     return PyDateTime_FromDateAndTime(
@@ -1141,8 +1114,7 @@ cms_profile_getattr_saturation_rendering_intent_gamut(
 static PyObject *
 cms_profile_getattr_red_colorant(CmsProfileObject *self, void *closure) {
     if (!cmsIsMatrixShaper(self->profile)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
     return _profile_read_ciexyz(self, cmsSigRedColorantTag, 0);
 }
@@ -1150,8 +1122,7 @@ cms_profile_getattr_red_colorant(CmsProfileObject *self, void *closure) {
 static PyObject *
 cms_profile_getattr_green_colorant(CmsProfileObject *self, void *closure) {
     if (!cmsIsMatrixShaper(self->profile)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
     return _profile_read_ciexyz(self, cmsSigGreenColorantTag, 0);
 }
@@ -1159,8 +1130,7 @@ cms_profile_getattr_green_colorant(CmsProfileObject *self, void *closure) {
 static PyObject *
 cms_profile_getattr_blue_colorant(CmsProfileObject *self, void *closure) {
     if (!cmsIsMatrixShaper(self->profile)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
     return _profile_read_ciexyz(self, cmsSigBlueColorantTag, 0);
 }
@@ -1176,21 +1146,18 @@ cms_profile_getattr_media_white_point_temperature(
     cmsBool result;
 
     if (!cmsIsTag(self->profile, info)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     XYZ = (cmsCIEXYZ *)cmsReadTag(self->profile, info);
     if (XYZ == NULL || XYZ->X == 0) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     cmsXYZ2xyY(&xyY, XYZ);
     result = cmsTempFromWhitePoint(&tempK, &xyY);
     if (!result) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
     return PyFloat_FromDouble(tempK);
 }
@@ -1229,8 +1196,7 @@ cms_profile_getattr_red_primary(CmsProfileObject *self, void *closure) {
         result = _calculate_rgb_primaries(self, &primaries);
     }
     if (!result) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     return _xyz_py(&primaries.Red);
@@ -1245,8 +1211,7 @@ cms_profile_getattr_green_primary(CmsProfileObject *self, void *closure) {
         result = _calculate_rgb_primaries(self, &primaries);
     }
     if (!result) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     return _xyz_py(&primaries.Green);
@@ -1261,8 +1226,7 @@ cms_profile_getattr_blue_primary(CmsProfileObject *self, void *closure) {
         result = _calculate_rgb_primaries(self, &primaries);
     }
     if (!result) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     return _xyz_py(&primaries.Blue);
@@ -1321,14 +1285,12 @@ cms_profile_getattr_icc_measurement_condition(CmsProfileObject *self, void *clos
     const char *geo;
 
     if (!cmsIsTag(self->profile, info)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     mc = (cmsICCMeasurementConditions *)cmsReadTag(self->profile, info);
     if (!mc) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     if (mc->Geometry == 1) {
@@ -1362,14 +1324,12 @@ cms_profile_getattr_icc_viewing_condition(CmsProfileObject *self, void *closure)
     cmsTagSignature info = cmsSigViewingConditionsTag;
 
     if (!cmsIsTag(self->profile, info)) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     vc = (cmsICCViewingConditions *)cmsReadTag(self->profile, info);
     if (!vc) {
-        Py_INCREF(Py_None);
-        return Py_None;
+        Py_RETURN_NONE;
     }
 
     return Py_BuildValue(
diff --git a/src/_imagingft.c b/src/_imagingft.c
index d38279f3e4b..dcff54b6c5c 100644
--- a/src/_imagingft.c
+++ b/src/_imagingft.c
@@ -18,10 +18,8 @@
  * Copyright (c) 1998-2007 by Secret Labs AB
  */
 
-#define PY_SSIZE_T_CLEAN
-#include "Python.h"
-#include "thirdparty/pythoncapi_compat.h"
 #include "libImaging/Imaging.h"
+#include "thirdparty/pythoncapi_compat.h"
 
 #include <ft2build.h>
 #include FT_FREETYPE_H
@@ -1377,8 +1375,7 @@ font_setvarname(FontObject *self, PyObject *args) {
         return geterror(error);
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -1432,8 +1429,7 @@ font_setvaraxes(FontObject *self, PyObject *args) {
         return geterror(error);
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 #endif
 
diff --git a/src/_imagingmath.c b/src/_imagingmath.c
index dbe636707f4..d54c6db56c3 100644
--- a/src/_imagingmath.c
+++ b/src/_imagingmath.c
@@ -13,12 +13,9 @@
  * See the README file for information on usage and redistribution.
  */
 
-#include "Python.h"
-
 #include "libImaging/Imaging.h"
 
-#include "math.h"
-#include "float.h"
+#include <float.h>
 
 #define MAX_INT32 2147483647.0
 #define MIN_INT32 -2147483648.0
@@ -63,8 +60,8 @@
 #define SUB(type, v1, v2) (v1) - (v2)
 #define MUL(type, v1, v2) (v1) * (v2)
 
-#define MIN(type, v1, v2) ((v1) < (v2)) ? (v1) : (v2)
-#define MAX(type, v1, v2) ((v1) > (v2)) ? (v1) : (v2)
+#define MINOP(type, v1, v2) ((v1) < (v2)) ? (v1) : (v2)
+#define MAXOP(type, v1, v2) ((v1) > (v2)) ? (v1) : (v2)
 
 #define AND(type, v1, v2) (v1) & (v2)
 #define OR(type, v1, v2) (v1) | (v2)
@@ -134,8 +131,8 @@ BINOP(xor_I, XOR, INT32)
 BINOP(lshift_I, LSHIFT, INT32)
 BINOP(rshift_I, RSHIFT, INT32)
 
-BINOP(min_I, MIN, INT32)
-BINOP(max_I, MAX, INT32)
+BINOP(min_I, MINOP, INT32)
+BINOP(max_I, MAXOP, INT32)
 
 BINOP(eq_I, EQ, INT32)
 BINOP(ne_I, NE, INT32)
@@ -155,8 +152,8 @@ BINOP(mod_F, MOD_F, FLOAT32)
 BINOP(pow_F, POW_F, FLOAT32)
 BINOP(diff_F, DIFF_F, FLOAT32)
 
-BINOP(min_F, MIN, FLOAT32)
-BINOP(max_F, MAX, FLOAT32)
+BINOP(min_F, MINOP, FLOAT32)
+BINOP(max_F, MAXOP, FLOAT32)
 
 BINOP(eq_F, EQ, FLOAT32)
 BINOP(ne_F, NE, FLOAT32)
@@ -192,8 +189,7 @@ _unop(PyObject *self, PyObject *args) {
 
     unop(out, im1);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -226,8 +222,7 @@ _binop(PyObject *self, PyObject *args) {
 
     binop(out, im1, im2);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyMethodDef _functions[] = {
diff --git a/src/_imagingtk.c b/src/_imagingtk.c
index c70d044bb86..03bda916378 100644
--- a/src/_imagingtk.c
+++ b/src/_imagingtk.c
@@ -12,7 +12,6 @@
  * See the README file for information on usage and redistribution.
  */
 
-#include "Python.h"
 #include "libImaging/Imaging.h"
 
 #include "Tk/_tkmini.h"
@@ -37,8 +36,7 @@ _tkinit(PyObject *self, PyObject *args) {
     /* This will bomb if interp is invalid... */
     TkImaging_Init(interp);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyMethodDef functions[] = {
diff --git a/src/_webp.c b/src/_webp.c
index dfda7048de4..cf6e999b1d6 100644
--- a/src/_webp.c
+++ b/src/_webp.c
@@ -1,6 +1,5 @@
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
 #include "libImaging/Imaging.h"
+
 #include <webp/encode.h>
 #include <webp/decode.h>
 #include <webp/types.h>
diff --git a/src/decode.c b/src/decode.c
index 51d0aced2bd..1660741d383 100644
--- a/src/decode.c
+++ b/src/decode.c
@@ -29,11 +29,7 @@
 
 /* FIXME: make these pluggable! */
 
-#define PY_SSIZE_T_CLEAN
-#include "Python.h"
-
 #include "libImaging/Imaging.h"
-
 #include "libImaging/Bit.h"
 #include "libImaging/Bcn.h"
 #include "libImaging/Gif.h"
@@ -213,8 +209,7 @@ _setimage(ImagingDecoderObject *decoder, PyObject *args) {
     Py_XDECREF(decoder->lock);
     decoder->lock = op;
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -231,8 +226,7 @@ _setfd(ImagingDecoderObject *decoder, PyObject *args) {
     Py_XINCREF(fd);
     state->fd = fd;
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -800,74 +794,6 @@ PyImaging_ZipDecoderNew(PyObject *self, PyObject *args) {
 }
 #endif
 
-/* -------------------------------------------------------------------- */
-/* JPEG                                                                 */
-/* -------------------------------------------------------------------- */
-
-#ifdef HAVE_LIBJPEG
-
-/* We better define this decoder last in this file, so the following
-   undef's won't mess things up for the Imaging library proper. */
-
-#undef HAVE_PROTOTYPES
-#undef HAVE_STDDEF_H
-#undef HAVE_STDLIB_H
-#undef UINT8
-#undef UINT16
-#undef UINT32
-#undef INT8
-#undef INT16
-#undef INT32
-
-#include "libImaging/Jpeg.h"
-
-PyObject *
-PyImaging_JpegDecoderNew(PyObject *self, PyObject *args) {
-    ImagingDecoderObject *decoder;
-
-    char *mode;
-    char *rawmode;  /* what we want from the decoder */
-    char *jpegmode; /* what's in the file */
-    int scale = 1;
-    int draft = 0;
-
-    if (!PyArg_ParseTuple(args, "ssz|ii", &mode, &rawmode, &jpegmode, &scale, &draft)) {
-        return NULL;
-    }
-
-    if (!jpegmode) {
-        jpegmode = "";
-    }
-
-    decoder = PyImaging_DecoderNew(sizeof(JPEGSTATE));
-    if (decoder == NULL) {
-        return NULL;
-    }
-
-    // libjpeg-turbo supports different output formats.
-    // We are choosing Pillow's native format (3 color bytes + 1 padding)
-    // to avoid extra conversion in Unpack.c.
-    if (ImagingJpegUseJCSExtensions() && strcmp(rawmode, "RGB") == 0) {
-        rawmode = "RGBX";
-    }
-
-    if (get_unpacker(decoder, mode, rawmode) < 0) {
-        return NULL;
-    }
-
-    decoder->decode = ImagingJpegDecode;
-    decoder->cleanup = ImagingJpegDecodeCleanup;
-
-    strncpy(((JPEGSTATE *)decoder->state.context)->rawmode, rawmode, 8);
-    strncpy(((JPEGSTATE *)decoder->state.context)->jpegmode, jpegmode, 8);
-
-    ((JPEGSTATE *)decoder->state.context)->scale = scale;
-    ((JPEGSTATE *)decoder->state.context)->draft = draft;
-
-    return (PyObject *)decoder;
-}
-#endif
-
 /* -------------------------------------------------------------------- */
 /* JPEG 2000                                                            */
 /* -------------------------------------------------------------------- */
@@ -925,3 +851,61 @@ PyImaging_Jpeg2KDecoderNew(PyObject *self, PyObject *args) {
     return (PyObject *)decoder;
 }
 #endif /* HAVE_OPENJPEG */
+
+/* -------------------------------------------------------------------- */
+/* JPEG                                                                 */
+/* -------------------------------------------------------------------- */
+
+#ifdef HAVE_LIBJPEG
+
+/* We better define this decoder last in this file, so the undef's
+   in Jpeg.h won't mess things up for the Imaging library proper. */
+
+#include "libImaging/Jpeg.h"
+
+PyObject *
+PyImaging_JpegDecoderNew(PyObject *self, PyObject *args) {
+    ImagingDecoderObject *decoder;
+
+    char *mode;
+    char *rawmode;  /* what we want from the decoder */
+    char *jpegmode; /* what's in the file */
+    int scale = 1;
+    int draft = 0;
+
+    if (!PyArg_ParseTuple(args, "ssz|ii", &mode, &rawmode, &jpegmode, &scale, &draft)) {
+        return NULL;
+    }
+
+    if (!jpegmode) {
+        jpegmode = "";
+    }
+
+    decoder = PyImaging_DecoderNew(sizeof(JPEGSTATE));
+    if (decoder == NULL) {
+        return NULL;
+    }
+
+    // libjpeg-turbo supports different output formats.
+    // We are choosing Pillow's native format (3 color bytes + 1 padding)
+    // to avoid extra conversion in Unpack.c.
+    if (ImagingJpegUseJCSExtensions() && strcmp(rawmode, "RGB") == 0) {
+        rawmode = "RGBX";
+    }
+
+    if (get_unpacker(decoder, mode, rawmode) < 0) {
+        return NULL;
+    }
+
+    decoder->decode = ImagingJpegDecode;
+    decoder->cleanup = ImagingJpegDecodeCleanup;
+
+    strncpy(((JPEGSTATE *)decoder->state.context)->rawmode, rawmode, 8);
+    strncpy(((JPEGSTATE *)decoder->state.context)->jpegmode, jpegmode, 8);
+
+    ((JPEGSTATE *)decoder->state.context)->scale = scale;
+    ((JPEGSTATE *)decoder->state.context)->draft = draft;
+
+    return (PyObject *)decoder;
+}
+#endif
diff --git a/src/display.c b/src/display.c
index eed75975d71..cf133ca86ae 100644
--- a/src/display.c
+++ b/src/display.c
@@ -22,9 +22,6 @@
  * See the README file for information on usage and redistribution.
  */
 
-#define PY_SSIZE_T_CLEAN
-#include "Python.h"
-
 #include "libImaging/Imaging.h"
 
 /* -------------------------------------------------------------------- */
@@ -34,12 +31,6 @@
 
 #include "libImaging/ImDib.h"
 
-#if SIZEOF_VOID_P == 8
-#define F_HANDLE "K"
-#else
-#define F_HANDLE "k"
-#endif
-
 typedef struct {
     PyObject_HEAD ImagingDIB dib;
 } ImagingDisplayObject;
@@ -85,8 +76,7 @@ _expose(ImagingDisplayObject *display, PyObject *args) {
 
     ImagingExposeDIB(display->dib, hdc);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -112,8 +102,7 @@ _draw(ImagingDisplayObject *display, PyObject *args) {
 
     ImagingDrawDIB(display->dib, hdc, dst, src);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 extern Imaging
@@ -143,8 +132,7 @@ _paste(ImagingDisplayObject *display, PyObject *args) {
 
     ImagingPasteDIB(display->dib, im, xy);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -190,8 +178,7 @@ _releasedc(ImagingDisplayObject *display, PyObject *args) {
 
     ReleaseDC(window, dc);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -211,8 +198,7 @@ _frombytes(ImagingDisplayObject *display, PyObject *args) {
     memcpy(display->dib->bits, buffer.buf, buffer.len);
 
     PyBuffer_Release(&buffer);
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -709,8 +695,7 @@ PyImaging_EventLoopWin32(PyObject *self, PyObject *args) {
     }
     Py_END_ALLOW_THREADS;
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 /* -------------------------------------------------------------------- */
diff --git a/src/encode.c b/src/encode.c
index d369a1b4598..244e218c4d8 100644
--- a/src/encode.c
+++ b/src/encode.c
@@ -22,11 +22,8 @@
 
 /* FIXME: make these pluggable! */
 
-#define PY_SSIZE_T_CLEAN
-#include "Python.h"
-
-#include "thirdparty/pythoncapi_compat.h"
 #include "libImaging/Imaging.h"
+#include "thirdparty/pythoncapi_compat.h"
 #include "libImaging/Gif.h"
 
 #ifdef HAVE_UNISTD_H
@@ -278,8 +275,7 @@ _setimage(ImagingEncoderObject *encoder, PyObject *args) {
     Py_XDECREF(encoder->lock);
     encoder->lock = op;
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -296,8 +292,7 @@ _setfd(ImagingEncoderObject *encoder, PyObject *args) {
     Py_XINCREF(fd);
     state->fd = fd;
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -986,24 +981,213 @@ PyImaging_LibTiffEncoderNew(PyObject *self, PyObject *args) {
 
 #endif
 
+/* -------------------------------------------------------------------- */
+/* JPEG 2000                                                            */
+/* -------------------------------------------------------------------- */
+
+#ifdef HAVE_OPENJPEG
+
+#include "libImaging/Jpeg2K.h"
+
+static void
+j2k_decode_coord_tuple(PyObject *tuple, int *x, int *y) {
+    *x = *y = 0;
+
+    if (tuple && PyTuple_Check(tuple) && PyTuple_GET_SIZE(tuple) == 2) {
+        *x = (int)PyLong_AsLong(PyTuple_GET_ITEM(tuple, 0));
+        *y = (int)PyLong_AsLong(PyTuple_GET_ITEM(tuple, 1));
+
+        if (*x < 0) {
+            *x = 0;
+        }
+        if (*y < 0) {
+            *y = 0;
+        }
+    }
+}
+
+PyObject *
+PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
+    ImagingEncoderObject *encoder;
+    JPEG2KENCODESTATE *context;
+
+    char *mode;
+    char *format;
+    OPJ_CODEC_FORMAT codec_format;
+    PyObject *offset = NULL, *tile_offset = NULL, *tile_size = NULL;
+    char *quality_mode = "rates";
+    PyObject *quality_layers = NULL;
+    Py_ssize_t num_resolutions = 0;
+    PyObject *cblk_size = NULL, *precinct_size = NULL;
+    PyObject *irreversible = NULL;
+    char *progression = "LRCP";
+    OPJ_PROG_ORDER prog_order;
+    char *cinema_mode = "no";
+    OPJ_CINEMA_MODE cine_mode;
+    char mct = 0;
+    int sgnd = 0;
+    Py_ssize_t fd = -1;
+    char *comment;
+    Py_ssize_t comment_size;
+    int plt = 0;
+
+    if (!PyArg_ParseTuple(
+            args,
+            "ss|OOOsOnOOOssbbnz#p",
+            &mode,
+            &format,
+            &offset,
+            &tile_offset,
+            &tile_size,
+            &quality_mode,
+            &quality_layers,
+            &num_resolutions,
+            &cblk_size,
+            &precinct_size,
+            &irreversible,
+            &progression,
+            &cinema_mode,
+            &mct,
+            &sgnd,
+            &fd,
+            &comment,
+            &comment_size,
+            &plt
+        )) {
+        return NULL;
+    }
+
+    if (strcmp(format, "j2k") == 0) {
+        codec_format = OPJ_CODEC_J2K;
+    } else if (strcmp(format, "jpt") == 0) {
+        codec_format = OPJ_CODEC_JPT;
+    } else if (strcmp(format, "jp2") == 0) {
+        codec_format = OPJ_CODEC_JP2;
+    } else {
+        return NULL;
+    }
+
+    if (strcmp(progression, "LRCP") == 0) {
+        prog_order = OPJ_LRCP;
+    } else if (strcmp(progression, "RLCP") == 0) {
+        prog_order = OPJ_RLCP;
+    } else if (strcmp(progression, "RPCL") == 0) {
+        prog_order = OPJ_RPCL;
+    } else if (strcmp(progression, "PCRL") == 0) {
+        prog_order = OPJ_PCRL;
+    } else if (strcmp(progression, "CPRL") == 0) {
+        prog_order = OPJ_CPRL;
+    } else {
+        return NULL;
+    }
+
+    if (strcmp(cinema_mode, "no") == 0) {
+        cine_mode = OPJ_OFF;
+    } else if (strcmp(cinema_mode, "cinema2k-24") == 0) {
+        cine_mode = OPJ_CINEMA2K_24;
+    } else if (strcmp(cinema_mode, "cinema2k-48") == 0) {
+        cine_mode = OPJ_CINEMA2K_48;
+    } else if (strcmp(cinema_mode, "cinema4k-24") == 0) {
+        cine_mode = OPJ_CINEMA4K_24;
+    } else {
+        return NULL;
+    }
+
+    encoder = PyImaging_EncoderNew(sizeof(JPEG2KENCODESTATE));
+    if (!encoder) {
+        return NULL;
+    }
+
+    encoder->encode = ImagingJpeg2KEncode;
+    encoder->cleanup = ImagingJpeg2KEncodeCleanup;
+    encoder->pushes_fd = 1;
+
+    context = (JPEG2KENCODESTATE *)encoder->state.context;
+
+    context->fd = fd;
+    context->format = codec_format;
+    context->offset_x = context->offset_y = 0;
+
+    j2k_decode_coord_tuple(offset, &context->offset_x, &context->offset_y);
+    j2k_decode_coord_tuple(
+        tile_offset, &context->tile_offset_x, &context->tile_offset_y
+    );
+    j2k_decode_coord_tuple(tile_size, &context->tile_size_x, &context->tile_size_y);
+
+    /* Error on illegal tile offsets */
+    if (context->tile_size_x && context->tile_size_y) {
+        if (context->tile_offset_x <= context->offset_x - context->tile_size_x ||
+            context->tile_offset_y <= context->offset_y - context->tile_size_y) {
+            PyErr_SetString(
+                PyExc_ValueError,
+                "JPEG 2000 tile offset too small; top left tile must "
+                "intersect image area"
+            );
+            Py_DECREF(encoder);
+            return NULL;
+        }
+
+        if (context->tile_offset_x > context->offset_x ||
+            context->tile_offset_y > context->offset_y) {
+            PyErr_SetString(
+                PyExc_ValueError, "JPEG 2000 tile offset too large to cover image area"
+            );
+            Py_DECREF(encoder);
+            return NULL;
+        }
+    }
+
+    if (comment && comment_size > 0) {
+        /* Size is stored as as an uint16, subtract 4 bytes for the header */
+        if (comment_size >= 65532) {
+            PyErr_SetString(PyExc_ValueError, "JPEG 2000 comment is too long");
+            Py_DECREF(encoder);
+            return NULL;
+        }
+
+        char *p = malloc(comment_size + 1);
+        if (!p) {
+            Py_DECREF(encoder);
+            return ImagingError_MemoryError();
+        }
+        memcpy(p, comment, comment_size);
+        p[comment_size] = '\0';
+        context->comment = p;
+    }
+
+    if (quality_layers && PySequence_Check(quality_layers)) {
+        context->quality_is_in_db = strcmp(quality_mode, "dB") == 0;
+        context->quality_layers = quality_layers;
+        Py_INCREF(quality_layers);
+    }
+
+    context->num_resolutions = num_resolutions;
+
+    j2k_decode_coord_tuple(cblk_size, &context->cblk_width, &context->cblk_height);
+    j2k_decode_coord_tuple(
+        precinct_size, &context->precinct_width, &context->precinct_height
+    );
+
+    context->irreversible = PyObject_IsTrue(irreversible);
+    context->progression = prog_order;
+    context->cinema_mode = cine_mode;
+    context->mct = mct;
+    context->sgnd = sgnd;
+    context->plt = plt;
+
+    return (PyObject *)encoder;
+}
+
+#endif
+
 /* -------------------------------------------------------------------- */
 /* JPEG                                                                 */
 /* -------------------------------------------------------------------- */
 
 #ifdef HAVE_LIBJPEG
 
-/* We better define this encoder last in this file, so the following
-   undef's won't mess things up for the Imaging library proper. */
-
-#undef HAVE_PROTOTYPES
-#undef HAVE_STDDEF_H
-#undef HAVE_STDLIB_H
-#undef UINT8
-#undef UINT16
-#undef UINT32
-#undef INT8
-#undef INT16
-#undef INT32
+/* We better define this decoder last in this file, so the undef's
+   in Jpeg.h won't mess things up for the Imaging library proper. */
 
 #include "libImaging/Jpeg.h"
 
@@ -1216,202 +1400,3 @@ PyImaging_JpegEncoderNew(PyObject *self, PyObject *args) {
 }
 
 #endif
-
-/* -------------------------------------------------------------------- */
-/* JPEG 2000                                                            */
-/* -------------------------------------------------------------------- */
-
-#ifdef HAVE_OPENJPEG
-
-#include "libImaging/Jpeg2K.h"
-
-static void
-j2k_decode_coord_tuple(PyObject *tuple, int *x, int *y) {
-    *x = *y = 0;
-
-    if (tuple && PyTuple_Check(tuple) && PyTuple_GET_SIZE(tuple) == 2) {
-        *x = (int)PyLong_AsLong(PyTuple_GET_ITEM(tuple, 0));
-        *y = (int)PyLong_AsLong(PyTuple_GET_ITEM(tuple, 1));
-
-        if (*x < 0) {
-            *x = 0;
-        }
-        if (*y < 0) {
-            *y = 0;
-        }
-    }
-}
-
-PyObject *
-PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
-    ImagingEncoderObject *encoder;
-    JPEG2KENCODESTATE *context;
-
-    char *mode;
-    char *format;
-    OPJ_CODEC_FORMAT codec_format;
-    PyObject *offset = NULL, *tile_offset = NULL, *tile_size = NULL;
-    char *quality_mode = "rates";
-    PyObject *quality_layers = NULL;
-    Py_ssize_t num_resolutions = 0;
-    PyObject *cblk_size = NULL, *precinct_size = NULL;
-    PyObject *irreversible = NULL;
-    char *progression = "LRCP";
-    OPJ_PROG_ORDER prog_order;
-    char *cinema_mode = "no";
-    OPJ_CINEMA_MODE cine_mode;
-    char mct = 0;
-    int sgnd = 0;
-    Py_ssize_t fd = -1;
-    char *comment;
-    Py_ssize_t comment_size;
-    int plt = 0;
-
-    if (!PyArg_ParseTuple(
-            args,
-            "ss|OOOsOnOOOssbbnz#p",
-            &mode,
-            &format,
-            &offset,
-            &tile_offset,
-            &tile_size,
-            &quality_mode,
-            &quality_layers,
-            &num_resolutions,
-            &cblk_size,
-            &precinct_size,
-            &irreversible,
-            &progression,
-            &cinema_mode,
-            &mct,
-            &sgnd,
-            &fd,
-            &comment,
-            &comment_size,
-            &plt
-        )) {
-        return NULL;
-    }
-
-    if (strcmp(format, "j2k") == 0) {
-        codec_format = OPJ_CODEC_J2K;
-    } else if (strcmp(format, "jpt") == 0) {
-        codec_format = OPJ_CODEC_JPT;
-    } else if (strcmp(format, "jp2") == 0) {
-        codec_format = OPJ_CODEC_JP2;
-    } else {
-        return NULL;
-    }
-
-    if (strcmp(progression, "LRCP") == 0) {
-        prog_order = OPJ_LRCP;
-    } else if (strcmp(progression, "RLCP") == 0) {
-        prog_order = OPJ_RLCP;
-    } else if (strcmp(progression, "RPCL") == 0) {
-        prog_order = OPJ_RPCL;
-    } else if (strcmp(progression, "PCRL") == 0) {
-        prog_order = OPJ_PCRL;
-    } else if (strcmp(progression, "CPRL") == 0) {
-        prog_order = OPJ_CPRL;
-    } else {
-        return NULL;
-    }
-
-    if (strcmp(cinema_mode, "no") == 0) {
-        cine_mode = OPJ_OFF;
-    } else if (strcmp(cinema_mode, "cinema2k-24") == 0) {
-        cine_mode = OPJ_CINEMA2K_24;
-    } else if (strcmp(cinema_mode, "cinema2k-48") == 0) {
-        cine_mode = OPJ_CINEMA2K_48;
-    } else if (strcmp(cinema_mode, "cinema4k-24") == 0) {
-        cine_mode = OPJ_CINEMA4K_24;
-    } else {
-        return NULL;
-    }
-
-    encoder = PyImaging_EncoderNew(sizeof(JPEG2KENCODESTATE));
-    if (!encoder) {
-        return NULL;
-    }
-
-    encoder->encode = ImagingJpeg2KEncode;
-    encoder->cleanup = ImagingJpeg2KEncodeCleanup;
-    encoder->pushes_fd = 1;
-
-    context = (JPEG2KENCODESTATE *)encoder->state.context;
-
-    context->fd = fd;
-    context->format = codec_format;
-    context->offset_x = context->offset_y = 0;
-
-    j2k_decode_coord_tuple(offset, &context->offset_x, &context->offset_y);
-    j2k_decode_coord_tuple(
-        tile_offset, &context->tile_offset_x, &context->tile_offset_y
-    );
-    j2k_decode_coord_tuple(tile_size, &context->tile_size_x, &context->tile_size_y);
-
-    /* Error on illegal tile offsets */
-    if (context->tile_size_x && context->tile_size_y) {
-        if (context->tile_offset_x <= context->offset_x - context->tile_size_x ||
-            context->tile_offset_y <= context->offset_y - context->tile_size_y) {
-            PyErr_SetString(
-                PyExc_ValueError,
-                "JPEG 2000 tile offset too small; top left tile must "
-                "intersect image area"
-            );
-            Py_DECREF(encoder);
-            return NULL;
-        }
-
-        if (context->tile_offset_x > context->offset_x ||
-            context->tile_offset_y > context->offset_y) {
-            PyErr_SetString(
-                PyExc_ValueError, "JPEG 2000 tile offset too large to cover image area"
-            );
-            Py_DECREF(encoder);
-            return NULL;
-        }
-    }
-
-    if (comment && comment_size > 0) {
-        /* Size is stored as as an uint16, subtract 4 bytes for the header */
-        if (comment_size >= 65532) {
-            PyErr_SetString(PyExc_ValueError, "JPEG 2000 comment is too long");
-            Py_DECREF(encoder);
-            return NULL;
-        }
-
-        char *p = malloc(comment_size + 1);
-        if (!p) {
-            Py_DECREF(encoder);
-            return ImagingError_MemoryError();
-        }
-        memcpy(p, comment, comment_size);
-        p[comment_size] = '\0';
-        context->comment = p;
-    }
-
-    if (quality_layers && PySequence_Check(quality_layers)) {
-        context->quality_is_in_db = strcmp(quality_mode, "dB") == 0;
-        context->quality_layers = quality_layers;
-        Py_INCREF(quality_layers);
-    }
-
-    context->num_resolutions = num_resolutions;
-
-    j2k_decode_coord_tuple(cblk_size, &context->cblk_width, &context->cblk_height);
-    j2k_decode_coord_tuple(
-        precinct_size, &context->precinct_width, &context->precinct_height
-    );
-
-    context->irreversible = PyObject_IsTrue(irreversible);
-    context->progression = prog_order;
-    context->cinema_mode = cine_mode;
-    context->mct = mct;
-    context->sgnd = sgnd;
-    context->plt = plt;
-
-    return (PyObject *)encoder;
-}
-
-#endif
diff --git a/src/libImaging/BoxBlur.c b/src/libImaging/BoxBlur.c
index ed91541fed4..41fb5f0d90f 100644
--- a/src/libImaging/BoxBlur.c
+++ b/src/libImaging/BoxBlur.c
@@ -1,8 +1,5 @@
 #include "Imaging.h"
 
-#define MAX(x, y) (((x) > (y)) ? (x) : (y))
-#define MIN(x, y) (((x) < (y)) ? (x) : (y))
-
 typedef UINT8 pixel[4];
 
 void static inline ImagingLineBoxBlur32(
diff --git a/src/libImaging/ColorLUT.c b/src/libImaging/ColorLUT.c
index 5559de689b2..33633f555d1 100644
--- a/src/libImaging/ColorLUT.c
+++ b/src/libImaging/ColorLUT.c
@@ -1,5 +1,4 @@
 #include "Imaging.h"
-#include <math.h>
 
 /* 8 bits for result. Table can overflow [0, 1.0] range,
    so we need extra bits for overflow and negative values.
diff --git a/src/libImaging/Convert.c b/src/libImaging/Convert.c
index c8f23426105..a5b2b89a7bc 100644
--- a/src/libImaging/Convert.c
+++ b/src/libImaging/Convert.c
@@ -34,9 +34,6 @@
 
 #include "Imaging.h"
 
-#define MAX(a, b) (a) > (b) ? (a) : (b)
-#define MIN(a, b) (a) < (b) ? (a) : (b)
-
 #define CLIP16(v) ((v) <= 0 ? 0 : (v) >= 65535 ? 65535 : (v))
 
 /* ITU-R Recommendation 601-2 (assuming nonlinear RGB) */
@@ -1672,15 +1669,9 @@ convert(
     }
 
     if (!convert) {
-#ifdef notdef
-        return (Imaging)ImagingError_ValueError("conversion not supported");
-#else
-        static char buf[100];
-        snprintf(
-            buf, 100, "conversion from %.10s to %.10s not supported", imIn->mode, mode
+        return (Imaging)PyErr_Format(
+            PyExc_ValueError, "conversion from %s to %s not supported", imIn->mode, mode
         );
-        return (Imaging)ImagingError_ValueError(buf);
-#endif
     }
 
     imOut = ImagingNew2Dirty(mode, imOut, imIn);
@@ -1749,15 +1740,12 @@ ImagingConvertTransparent(Imaging imIn, const char *mode, int r, int g, int b) {
         }
         g = b = r;
     } else {
-        static char buf[100];
-        snprintf(
-            buf,
-            100,
-            "conversion from %.10s to %.10s not supported in convert_transparent",
+        return (Imaging)PyErr_Format(
+            PyExc_ValueError,
+            "conversion from %s to %s not supported in convert_transparent",
             imIn->mode,
             mode
         );
-        return (Imaging)ImagingError_ValueError(buf);
     }
 
     imOut = ImagingNew2Dirty(mode, imOut, imIn);
diff --git a/src/libImaging/Dib.c b/src/libImaging/Dib.c
index c69e9e552ae..a34fba85aa2 100644
--- a/src/libImaging/Dib.c
+++ b/src/libImaging/Dib.c
@@ -19,10 +19,9 @@
  * See the README file for information on usage and redistribution.
  */
 
-#include "Imaging.h"
-
 #ifdef _WIN32
 
+#include "Imaging.h"
 #include "ImDib.h"
 
 char *
diff --git a/src/libImaging/Draw.c b/src/libImaging/Draw.c
index ea6f8805efb..943638028a3 100644
--- a/src/libImaging/Draw.c
+++ b/src/libImaging/Draw.c
@@ -34,9 +34,6 @@
 
 #include "Imaging.h"
 
-#include <math.h>
-#include <stdint.h>
-
 #define CEIL(v) (int)ceil(v)
 #define FLOOR(v) ((v) >= 0.0 ? (int)(v) : (int)floor(v))
 
diff --git a/src/libImaging/Effects.c b/src/libImaging/Effects.c
index 93e7af0bce9..64d6188d917 100644
--- a/src/libImaging/Effects.c
+++ b/src/libImaging/Effects.c
@@ -17,8 +17,6 @@
 
 #include "Imaging.h"
 
-#include <math.h>
-
 Imaging
 ImagingEffectMandelbrot(int xsize, int ysize, double extent[4], int quality) {
     /* Generate a Mandelbrot set covering the given extent */
diff --git a/src/libImaging/Except.c b/src/libImaging/Except.c
deleted file mode 100644
index f42ff9aec9e..00000000000
--- a/src/libImaging/Except.c
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * The Python Imaging Library
- * $Id$
- *
- * default exception handling
- *
- * This module is usually overridden by application code (e.g.
- * _imaging.c for PIL's standard Python bindings).  If you get
- * linking errors, remove this file from your project/library.
- *
- * history:
- * 1995-06-15 fl   Created
- * 1998-12-29 fl   Minor tweaks
- * 2003-09-13 fl   Added ImagingEnter/LeaveSection()
- *
- * Copyright (c) 1997-2003 by Secret Labs AB.
- * Copyright (c) 1995-2003 by Fredrik Lundh.
- *
- * See the README file for information on usage and redistribution.
- */
-
-#include "Imaging.h"
-
-/* exception state */
-
-void *
-ImagingError_OSError(void) {
-    fprintf(stderr, "*** exception: file access error\n");
-    return NULL;
-}
-
-void *
-ImagingError_MemoryError(void) {
-    fprintf(stderr, "*** exception: out of memory\n");
-    return NULL;
-}
-
-void *
-ImagingError_ModeError(void) {
-    return ImagingError_ValueError("bad image mode");
-}
-
-void *
-ImagingError_Mismatch(void) {
-    return ImagingError_ValueError("images don't match");
-}
-
-void *
-ImagingError_ValueError(const char *message) {
-    if (!message) {
-        message = "exception: bad argument to function";
-    }
-    fprintf(stderr, "*** %s\n", message);
-    return NULL;
-}
-
-void
-ImagingError_Clear(void) {
-    /* nop */;
-}
-
-/* thread state */
-
-void
-ImagingSectionEnter(ImagingSectionCookie *cookie) {
-    /* pass */
-}
-
-void
-ImagingSectionLeave(ImagingSectionCookie *cookie) {
-    /* pass */
-}
diff --git a/src/libImaging/File.c b/src/libImaging/File.c
index 76d0abccc4f..901fe83ad27 100644
--- a/src/libImaging/File.c
+++ b/src/libImaging/File.c
@@ -54,7 +54,7 @@ ImagingSavePPM(Imaging im, const char *outfile) {
 
     fp = fopen(outfile, "wb");
     if (!fp) {
-        (void)ImagingError_OSError();
+        PyErr_SetString(PyExc_OSError, "error when accessing file");
         return 0;
     }
 
diff --git a/src/libImaging/Fill.c b/src/libImaging/Fill.c
index 8fb481e7e4d..1e4bb9ba0b5 100644
--- a/src/libImaging/Fill.c
+++ b/src/libImaging/Fill.c
@@ -17,8 +17,6 @@
 
 #include "Imaging.h"
 
-#include "math.h"
-
 Imaging
 ImagingFill(Imaging im, const void *colour) {
     int x, y;
diff --git a/src/libImaging/ImDib.h b/src/libImaging/ImDib.h
index 91ff3f322ff..a0c2348fd08 100644
--- a/src/libImaging/ImDib.h
+++ b/src/libImaging/ImDib.h
@@ -12,8 +12,6 @@
 
 #ifdef _WIN32
 
-#include "ImPlatform.h"
-
 #if defined(__cplusplus)
 extern "C" {
 #endif
diff --git a/src/libImaging/Imaging.h b/src/libImaging/Imaging.h
index 31052c68a97..945d861a5c5 100644
--- a/src/libImaging/Imaging.h
+++ b/src/libImaging/Imaging.h
@@ -10,16 +10,12 @@
  * See the README file for information on usage and redistribution.
  */
 
-#include "ImPlatform.h"
+#include "ImagingPlatform.h"
 
 #if defined(__cplusplus)
 extern "C" {
 #endif
 
-#ifndef M_PI
-#define M_PI 3.1415926535897932384626433832795
-#endif
-
 /* -------------------------------------------------------------------- */
 
 /*
@@ -241,8 +237,6 @@ ImagingSectionLeave(ImagingSectionCookie *cookie);
 /* Exceptions */
 /* ---------- */
 
-extern void *
-ImagingError_OSError(void);
 extern void *
 ImagingError_MemoryError(void);
 extern void *
@@ -251,8 +245,6 @@ extern void *
 ImagingError_Mismatch(void); /* maps to ValueError by default */
 extern void *
 ImagingError_ValueError(const char *message);
-extern void
-ImagingError_Clear(void);
 
 /* Transform callbacks */
 /* ------------------- */
@@ -609,10 +601,6 @@ ImagingLibTiffDecode(
 extern int
 ImagingLibTiffEncode(Imaging im, ImagingCodecState state, UINT8 *buffer, int bytes);
 #endif
-#ifdef HAVE_LIBMPEG
-extern int
-ImagingMpegDecode(Imaging im, ImagingCodecState state, UINT8 *buffer, Py_ssize_t bytes);
-#endif
 extern int
 ImagingMspDecode(Imaging im, ImagingCodecState state, UINT8 *buffer, Py_ssize_t bytes);
 extern int
diff --git a/src/libImaging/ImPlatform.h b/src/libImaging/ImagingPlatform.h
similarity index 52%
rename from src/libImaging/ImPlatform.h
rename to src/libImaging/ImagingPlatform.h
index c9b7e43b425..635ade21c88 100644
--- a/src/libImaging/ImPlatform.h
+++ b/src/libImaging/ImagingPlatform.h
@@ -8,7 +8,10 @@
  */
 
 #define PY_SSIZE_T_CLEAN
-#include "Python.h"
+#include <Python.h>
+
+#define _USE_MATH_DEFINES
+#include <math.h>
 
 /* Check that we have an ANSI compliant compiler */
 #ifndef HAVE_PROTOTYPES
@@ -18,36 +21,25 @@
 #error Sorry, this library requires ANSI header files.
 #endif
 
-#if defined(PIL_NO_INLINE)
-#define inline
-#else
 #if defined(_MSC_VER) && !defined(__GNUC__)
 #define inline __inline
 #endif
-#endif
-
-#if defined(_WIN32) || defined(__CYGWIN__) /* WIN */
 
+#ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN
 #include <Windows.h>
-
-#ifdef __CYGWIN__
-#undef _WIN64
-#undef _WIN32
-#undef __WIN32__
-#undef WIN32
+#ifdef _WIN64
+#define F_HANDLE "K"
+#else
+#define F_HANDLE "k"
 #endif
-
-#else /* not WIN */
-/* For System that are not Windows, we'll need to define these. */
-/* We have to define them instead of using typedef because the JPEG lib also
-   defines their own types with the same names, so we need to be able to undef
-   ours before including the JPEG code. */
-
-#if __STDC_VERSION__ >= 199901L /* C99+ */
+#endif /* _WIN32 */
 
 #include <stdint.h>
 
+/* We have to define types instead of using typedef because the JPEG lib also
+   defines their own types with the same names, so we need to be able to undef
+   ours before including the JPEG code. */
 #define INT8 int8_t
 #define UINT8 uint8_t
 #define INT16 int16_t
@@ -55,45 +47,11 @@
 #define INT32 int32_t
 #define UINT32 uint32_t
 
-#else /* < C99 */
-
-#define INT8 signed char
-
-#if SIZEOF_SHORT == 2
-#define INT16 short
-#elif SIZEOF_INT == 2
-#define INT16 int
-#else
-#error Cannot find required 16-bit integer type
-#endif
-
-#if SIZEOF_SHORT == 4
-#define INT32 short
-#elif SIZEOF_INT == 4
-#define INT32 int
-#elif SIZEOF_LONG == 4
-#define INT32 long
-#else
-#error Cannot find required 32-bit integer type
-#endif
-
-#define UINT8 unsigned char
-#define UINT16 unsigned INT16
-#define UINT32 unsigned INT32
-
-#endif /* < C99 */
-
-#endif /* not WIN */
-
 /* assume IEEE; tweak if necessary (patches are welcome) */
 #define FLOAT16 UINT16
 #define FLOAT32 float
 #define FLOAT64 double
 
-#ifdef _MSC_VER
-typedef signed __int64 int64_t;
-#endif
-
 #ifdef __GNUC__
 #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
 #endif
diff --git a/src/libImaging/ImagingUtils.h b/src/libImaging/ImagingUtils.h
index 714458ad02a..e8045506980 100644
--- a/src/libImaging/ImagingUtils.h
+++ b/src/libImaging/ImagingUtils.h
@@ -14,6 +14,9 @@
 #define MASK_UINT32_CHANNEL_3 0xff000000
 #endif
 
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
 #define SHIFTFORDIV255(a) ((((a) >> 8) + a) >> 8)
 
 /* like (a * b + 127) / 255), but much faster on most platforms */
diff --git a/src/libImaging/Jpeg.h b/src/libImaging/Jpeg.h
index 7cdba902281..f59f7909e9a 100644
--- a/src/libImaging/Jpeg.h
+++ b/src/libImaging/Jpeg.h
@@ -8,7 +8,16 @@
  * Copyright (c) 1995-1996 by Fredrik Lundh
  */
 
-#include "jpeglib.h"
+/* These undefs are required for libjpeg v8 and below */
+
+#undef UINT8
+#undef UINT16
+#undef UINT32
+#undef INT8
+#undef INT16
+#undef INT32
+
+#include <jpeglib.h>
 
 #include <setjmp.h>
 
diff --git a/src/libImaging/Jpeg2KDecode.c b/src/libImaging/Jpeg2KDecode.c
index 4f185b529ac..7b0564c9bb8 100644
--- a/src/libImaging/Jpeg2KDecode.c
+++ b/src/libImaging/Jpeg2KDecode.c
@@ -17,7 +17,6 @@
 
 #ifdef HAVE_OPENJPEG
 
-#include <stdlib.h>
 #include "Jpeg2K.h"
 
 typedef struct {
diff --git a/src/libImaging/JpegDecode.c b/src/libImaging/JpegDecode.c
index 2970f56d1af..838a7483cdd 100644
--- a/src/libImaging/JpegDecode.c
+++ b/src/libImaging/JpegDecode.c
@@ -25,15 +25,6 @@
 
 #ifdef HAVE_LIBJPEG
 
-#undef HAVE_PROTOTYPES
-#undef HAVE_STDLIB_H
-#undef HAVE_STDDEF_H
-#undef UINT8
-#undef UINT16
-#undef UINT32
-#undef INT16
-#undef INT32
-
 #include "Jpeg.h"
 
 #define STRINGIFY(x) #x
diff --git a/src/libImaging/JpegEncode.c b/src/libImaging/JpegEncode.c
index 4372d51d5c3..880a3111794 100644
--- a/src/libImaging/JpegEncode.c
+++ b/src/libImaging/JpegEncode.c
@@ -23,15 +23,6 @@
 
 #ifdef HAVE_LIBJPEG
 
-#undef HAVE_PROTOTYPES
-#undef HAVE_STDLIB_H
-#undef HAVE_STDDEF_H
-#undef UINT8
-#undef UINT16
-#undef UINT32
-#undef INT16
-#undef INT32
-
 #include "Jpeg.h"
 
 /* -------------------------------------------------------------------- */
diff --git a/src/libImaging/Palette.c b/src/libImaging/Palette.c
index 78916bca52b..032ce8ab26a 100644
--- a/src/libImaging/Palette.c
+++ b/src/libImaging/Palette.c
@@ -18,8 +18,6 @@
 
 #include "Imaging.h"
 
-#include <math.h>
-
 ImagingPalette
 ImagingPaletteNew(const char *mode) {
     /* Create a palette object */
diff --git a/src/libImaging/Quant.c b/src/libImaging/Quant.c
index a489a882db2..147d8ae52cb 100644
--- a/src/libImaging/Quant.c
+++ b/src/libImaging/Quant.c
@@ -1428,7 +1428,6 @@ quantize(
     }
 
 #ifdef TEST_NEAREST_NEIGHBOUR
-#include <math.h>
     {
         uint32_t bestmatch, bestdist, dist;
         HashTable *h2;
diff --git a/src/libImaging/QuantOctree.c b/src/libImaging/QuantOctree.c
index ec60b214ef1..be1b239a26f 100644
--- a/src/libImaging/QuantOctree.c
+++ b/src/libImaging/QuantOctree.c
@@ -28,7 +28,7 @@
 #include <string.h>
 #include <limits.h>
 
-#include "ImagingUtils.h"
+#include "Imaging.h"
 #include "QuantOctree.h"
 
 typedef struct _ColorBucket {
@@ -49,8 +49,6 @@ typedef struct _ColorCube {
     ColorBucket buckets;
 } *ColorCube;
 
-#define MAX(a, b) (a) > (b) ? (a) : (b)
-
 static ColorCube
 new_color_cube(int r, int g, int b, int a) {
     ColorCube cube;
diff --git a/src/libImaging/QuantPngQuant.c b/src/libImaging/QuantPngQuant.c
index a2258c3a289..52f12751532 100644
--- a/src/libImaging/QuantPngQuant.c
+++ b/src/libImaging/QuantPngQuant.c
@@ -8,15 +8,15 @@
  *
  */
 
+#ifdef HAVE_LIBIMAGEQUANT
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <libimagequant.h>
 
 #include "QuantPngQuant.h"
 
-#ifdef HAVE_LIBIMAGEQUANT
-#include "libimagequant.h"
-
 int
 quantize_pngquant(
     Pixel *pixelData,
diff --git a/src/libImaging/QuantTypes.h b/src/libImaging/QuantTypes.h
index 986b70806dc..e01023de7e1 100644
--- a/src/libImaging/QuantTypes.h
+++ b/src/libImaging/QuantTypes.h
@@ -9,15 +9,10 @@
  * See the README file for information on usage and redistribution.
  */
 
-#ifndef __TYPES_H__
-#define __TYPES_H__
+#ifndef __QUANTTYPES_H__
+#define __QUANTTYPES_H__
 
-#ifdef _MSC_VER
-typedef unsigned __int32 uint32_t;
-typedef unsigned __int64 uint64_t;
-#else
 #include <stdint.h>
-#endif
 
 typedef union {
     struct {
diff --git a/src/libImaging/Reduce.c b/src/libImaging/Reduce.c
index 022daa0003f..6da18d773d5 100644
--- a/src/libImaging/Reduce.c
+++ b/src/libImaging/Reduce.c
@@ -1,7 +1,5 @@
 #include "Imaging.h"
 
-#include <math.h>
-
 #define ROUND_UP(f) ((int)((f) >= 0.0 ? (f) + 0.5F : (f) - 0.5F))
 
 UINT32
diff --git a/src/libImaging/Resample.c b/src/libImaging/Resample.c
index f5e386dc2ba..978bf74c750 100644
--- a/src/libImaging/Resample.c
+++ b/src/libImaging/Resample.c
@@ -1,7 +1,5 @@
 #include "Imaging.h"
 
-#include <math.h>
-
 #define ROUND_UP(f) ((int)((f) >= 0.0 ? (f) + 0.5F : (f) - 0.5F))
 
 struct filter {
diff --git a/src/libImaging/Storage.c b/src/libImaging/Storage.c
index 522e9f37557..634ad71bfc4 100644
--- a/src/libImaging/Storage.c
+++ b/src/libImaging/Storage.c
@@ -513,7 +513,7 @@ ImagingNewInternal(const char *mode, int xsize, int ysize, int dirty) {
         return im;
     }
 
-    ImagingError_Clear();
+    PyErr_Clear();
 
     // Try to allocate the image once more with smallest possible block size
     MUTEX_LOCK(&ImagingDefaultArena.mutex);
diff --git a/src/libImaging/TiffDecode.c b/src/libImaging/TiffDecode.c
index e4da9162dc9..a4ce042eb41 100644
--- a/src/libImaging/TiffDecode.c
+++ b/src/libImaging/TiffDecode.c
@@ -69,7 +69,7 @@ _tiffReadProc(thandle_t hdata, tdata_t buf, tsize_t size) {
         );
         return 0;
     }
-    to_read = min(size, min(state->size, (tsize_t)state->eof) - (tsize_t)state->loc);
+    to_read = MIN(size, MIN(state->size, (tsize_t)state->eof) - (tsize_t)state->loc);
     TRACE(("to_read: %d\n", (int)to_read));
 
     _TIFFmemcpy(buf, (UINT8 *)state->data + state->loc, to_read);
@@ -87,7 +87,7 @@ _tiffWriteProc(thandle_t hdata, tdata_t buf, tsize_t size) {
     TRACE(("_tiffWriteProc: %d \n", (int)size));
     dump_state(state);
 
-    to_write = min(size, state->size - (tsize_t)state->loc);
+    to_write = MIN(size, state->size - (tsize_t)state->loc);
     if (state->flrealloc && size > to_write) {
         tdata_t new_data;
         tsize_t newsize = state->size;
@@ -114,7 +114,7 @@ _tiffWriteProc(thandle_t hdata, tdata_t buf, tsize_t size) {
 
     _TIFFmemcpy((UINT8 *)state->data + state->loc, buf, to_write);
     state->loc += (toff_t)to_write;
-    state->eof = max(state->loc, state->eof);
+    state->eof = MAX(state->loc, state->eof);
 
     dump_state(state);
     return to_write;
@@ -333,7 +333,7 @@ _decodeAsRGBA(Imaging im, ImagingCodecState state, TIFF *tiff) {
 
     for (; state->y < state->ysize; state->y += rows_per_block) {
         img.row_offset = state->y;
-        rows_to_read = min(rows_per_block, img.height - state->y);
+        rows_to_read = MIN(rows_per_block, img.height - state->y);
 
         if (!TIFFRGBAImageGet(&img, (UINT32 *)state->buffer, img.width, rows_to_read)) {
             TRACE(("Decode Error, y: %d\n", state->y));
@@ -349,7 +349,7 @@ _decodeAsRGBA(Imaging im, ImagingCodecState state, TIFF *tiff) {
 
         // iterate over each row in the strip and stuff data into image
         for (current_row = 0;
-             current_row < min((INT32)rows_per_block, state->ysize - state->y);
+             current_row < MIN((INT32)rows_per_block, state->ysize - state->y);
              current_row++) {
             TRACE(("Writing data into line %d ; \n", state->y + current_row));
 
@@ -452,8 +452,8 @@ _decodeTile(
 
                 TRACE(("Read tile at %dx%d; \n\n", x, y));
 
-                current_tile_width = min((INT32)tile_width, state->xsize - x);
-                current_tile_length = min((INT32)tile_length, state->ysize - y);
+                current_tile_width = MIN((INT32)tile_width, state->xsize - x);
+                current_tile_length = MIN((INT32)tile_length, state->ysize - y);
                 // iterate over each line in the tile and stuff data into image
                 for (tile_y = 0; tile_y < current_tile_length; tile_y++) {
                     TRACE(
@@ -566,7 +566,7 @@ _decodeStrip(
 
             // iterate over each row in the strip and stuff data into image
             for (strip_row = 0;
-                 strip_row < min((INT32)rows_per_strip, state->ysize - state->y);
+                 strip_row < MIN((INT32)rows_per_strip, state->ysize - state->y);
                  strip_row++) {
                 TRACE(("Writing data into line %d ; \n", state->y + strip_row));
 
diff --git a/src/libImaging/TiffDecode.h b/src/libImaging/TiffDecode.h
index 22361210dcb..0768fb67496 100644
--- a/src/libImaging/TiffDecode.h
+++ b/src/libImaging/TiffDecode.h
@@ -6,20 +6,8 @@
  *
  */
 
-#ifndef _TIFFIO_
 #include <tiffio.h>
-#endif
-#ifndef _TIFF_
 #include <tiff.h>
-#endif
-
-#ifndef min
-#define min(x, y) ((x > y) ? y : x)
-#define max(x, y) ((x < y) ? y : x)
-#endif
-
-#ifndef _PIL_LIBTIFF_
-#define _PIL_LIBTIFF_
 
 typedef struct {
     tdata_t data; /* tdata_t == void* */
@@ -57,5 +45,3 @@ ImagingLibTiffSetField(ImagingCodecState state, ttag_t tag, ...);
 */
 
 #define TRACE(args)
-
-#endif
diff --git a/src/libImaging/ZipCodecs.h b/src/libImaging/ZipCodecs.h
index 50218b6c69a..42f1a710150 100644
--- a/src/libImaging/ZipCodecs.h
+++ b/src/libImaging/ZipCodecs.h
@@ -7,7 +7,7 @@
  * Copyright (c) Fredrik Lundh 1996.
  */
 
-#include "zlib.h"
+#include <zlib.h>
 
 /* modes */
 #define ZIP_PNG 0            /* continuous, filtered image data */
diff --git a/src/libImaging/codec_fd.c b/src/libImaging/codec_fd.c
index 5261681107b..f5541c332f2 100644
--- a/src/libImaging/codec_fd.c
+++ b/src/libImaging/codec_fd.c
@@ -1,4 +1,3 @@
-#include "Python.h"
 #include "Imaging.h"
 
 Py_ssize_t
diff --git a/src/map.c b/src/map.c
index c66702981d3..ee0848cfb6c 100644
--- a/src/map.c
+++ b/src/map.c
@@ -18,16 +18,8 @@
  * FIXME: should move the memory mapping primitives into libImaging!
  */
 
-#include "Python.h"
-
 #include "libImaging/Imaging.h"
 
-/* compatibility wrappers (defined in _imaging.c) */
-extern int
-PyImaging_CheckBuffer(PyObject *buffer);
-extern int
-PyImaging_GetBuffer(PyObject *buffer, Py_buffer *view);
-
 extern PyObject *
 PyImagingNew(Imaging im);
 
@@ -77,7 +69,7 @@ PyImaging_MapBuffer(PyObject *self, PyObject *args) {
         return NULL;
     }
 
-    if (!PyImaging_CheckBuffer(target)) {
+    if (!PyObject_CheckBuffer(target)) {
         PyErr_SetString(PyExc_TypeError, "expected string or buffer");
         return NULL;
     }
@@ -105,7 +97,7 @@ PyImaging_MapBuffer(PyObject *self, PyObject *args) {
     }
 
     /* check buffer size */
-    if (PyImaging_GetBuffer(target, &view) < 0) {
+    if (PyObject_GetBuffer(target, &view, PyBUF_SIMPLE) < 0) {
         return NULL;
     }
 
diff --git a/src/outline.c b/src/outline.c
index 27cc255cf84..d5e47caf79f 100644
--- a/src/outline.c
+++ b/src/outline.c
@@ -17,8 +17,6 @@
  * See the README file for information on usage and redistribution.
  */
 
-#include "Python.h"
-
 #include "libImaging/Imaging.h"
 
 /* -------------------------------------------------------------------- */
@@ -89,8 +87,7 @@ _outline_move(OutlineObject *self, PyObject *args) {
 
     ImagingOutlineMove(self->outline, x0, y0);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -102,8 +99,7 @@ _outline_line(OutlineObject *self, PyObject *args) {
 
     ImagingOutlineLine(self->outline, x1, y1);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -115,8 +111,7 @@ _outline_curve(OutlineObject *self, PyObject *args) {
 
     ImagingOutlineCurve(self->outline, x1, y1, x2, y2, x3, y3);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -127,8 +122,7 @@ _outline_close(OutlineObject *self, PyObject *args) {
 
     ImagingOutlineClose(self->outline);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static PyObject *
@@ -140,8 +134,7 @@ _outline_transform(OutlineObject *self, PyObject *args) {
 
     ImagingOutlineTransform(self->outline, a);
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static struct PyMethodDef _outline_methods[] = {
diff --git a/src/path.c b/src/path.c
index 067f42f62de..e83e35d2a90 100644
--- a/src/path.c
+++ b/src/path.c
@@ -25,17 +25,8 @@
  * See the README file for information on usage and redistribution.
  */
 
-#include "Python.h"
-#include "thirdparty/pythoncapi_compat.h"
 #include "libImaging/Imaging.h"
-
-#include <math.h>
-
-/* compatibility wrappers (defined in _imaging.c) */
-extern int
-PyImaging_CheckBuffer(PyObject *buffer);
-extern int
-PyImaging_GetBuffer(PyObject *buffer, Py_buffer *view);
+#include "thirdparty/pythoncapi_compat.h"
 
 /* -------------------------------------------------------------------- */
 /* Class                                                                */
@@ -126,10 +117,10 @@ PyPath_Flatten(PyObject *data, double **pxy) {
         return path->count;
     }
 
-    if (PyImaging_CheckBuffer(data)) {
+    if (PyObject_CheckBuffer(data)) {
         /* Assume the buffer contains floats */
         Py_buffer buffer;
-        if (PyImaging_GetBuffer(data, &buffer) == 0) {
+        if (PyObject_GetBuffer(data, &buffer, PyBUF_SIMPLE) == 0) {
             float *ptr = (float *)buffer.buf;
             n = buffer.len / (2 * sizeof(float));
             xy = alloc_array(n);
@@ -415,8 +406,7 @@ path_map(PyPathObject *self, PyObject *args) {
     }
     self->mapping = 0;
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static int
@@ -528,8 +518,7 @@ path_transform(PyPathObject *self, PyObject *args) {
         }
     }
 
-    Py_INCREF(Py_None);
-    return Py_None;
+    Py_RETURN_NONE;
 }
 
 static struct PyMethodDef methods[] = {