diff --git a/DESCRIPTION b/DESCRIPTION
index f59a3fe..304e3d7 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -55,7 +55,6 @@ Collate:
     'change.R'
     'color.R'
     'compare.R'
-    'ggplot2.R'
     'info.R'
     'khroma-deprecated.R'
     'khroma-internal.R'
@@ -70,5 +69,6 @@ Collate:
     'scale_colour_crameri.R'
     'scale_colour_okabeito.R'
     'scale_colour_other.R'
+    'scale_colour_picker.R'
     'scale_colour_science.R'
     'scale_colour_tol.R'
diff --git a/NEWS.md b/NEWS.md
index ec56d95..b5264c2 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -10,6 +10,7 @@
 * `plot*()` functions invisibly return the first argument (vector of colors).
 * Deprecate `convert()` (#14).
 * Deprecate `ramp()`.
+* Remove deprecated argument in `ggplot2::discrete_scale()` and `ggplot2::continuous_scale()` (#15).
 
 # khroma 1.12.0
 ## New functions
diff --git a/R/ggplot2.R b/R/scale_colour_picker.R
similarity index 85%
rename from R/ggplot2.R
rename to R/scale_colour_picker.R
index 317c92f..6ade3bc 100644
--- a/R/ggplot2.R
+++ b/R/scale_colour_picker.R
@@ -12,7 +12,7 @@ NULL
 #'  [continuous][ggplot2::continuous_scale] scale.
 #' @example inst/examples/ex-pick.R
 #' @author N. Frerebeau
-#' @family color scales
+#' @family ggplot2 scales
 #' @name scale_picker
 #' @rdname scale_picker
 NULL
@@ -58,7 +58,7 @@ scale_edge_fill_picker <- function(..., palette = "YlOrBr") {
 #' Builds a discrete or continuous scale for \pkg{ggplot2} according to the
 #' color scheme used.
 #' @param aesthetics The names of the aesthetics that this scale works with.
-#' @param scale_name A [`character`] string giving the name of the palette to be
+#' @param scheme A [`character`] string giving the name of the scheme to be
 #'  used (see [color()]).
 #' @param guide A [`function`] used to create a guide or its name.
 #'  See [ggplot2::guides()] for more information.
@@ -85,15 +85,14 @@ scale_edge_fill_picker <- function(..., palette = "YlOrBr") {
 #' @noRd
 NULL
 
-scale_discrete <- function(aesthetics, scale_name, guide = "legend",
+scale_discrete <- function(aesthetics, scheme, guide = "legend",
                            reverse = FALSE, use_names = FALSE,
                            lang = "en", ...) {
   # Check if ggplot2 is installed
   check_package("ggplot2")
 
   # Get color scheme
-  palette <- color(scale_name, reverse = reverse, names = use_names,
-                   lang = lang)
+  palette <- color(scheme, reverse = reverse, names = use_names, lang = lang)
 
   # Build scale
   scale_args <- list(...)
@@ -101,11 +100,12 @@ scale_discrete <- function(aesthetics, scale_name, guide = "legend",
   scale_args$na.value <- scale_args$na.value %||% attr(palette, "missing")
 
   do.call(
-    ggplot2::discrete_scale, c(aesthetics, scale_name, palette, scale_args)
+    ggplot2::discrete_scale,
+    c(aesthetics = aesthetics, palette = palette, scale_args)
   )
 }
 
-scale_continuous <- function(aesthetics, scale_name, guide = "colourbar",
+scale_continuous <- function(aesthetics, scheme, guide = "colourbar",
                              reverse = FALSE, range = c(0, 1), midpoint = 0,
                              lang = "en", ...) {
   # Validation
@@ -113,7 +113,7 @@ scale_continuous <- function(aesthetics, scale_name, guide = "colourbar",
   if (guide == "edge_colourbar") check_package("ggraph")
 
   # Get color scheme
-  palette <- color(scale_name, reverse = reverse, names = FALSE, lang = lang)
+  palette <- color(scheme, reverse = reverse, names = FALSE, lang = lang)
   max <- attr(palette, "max")
   type <- attr(palette, "type")
 
@@ -128,12 +128,13 @@ scale_continuous <- function(aesthetics, scale_name, guide = "colourbar",
 
   palette <- scales::gradient_n_pal(palette(max, range = range))
   do.call(
-    ggplot2::continuous_scale, c(aesthetics, scale_name, palette, scale_args)
+    ggplot2::continuous_scale,
+    c(aesthetics = aesthetics, palette = palette, scale_args)
   )
 }
 
 rescale_mid <- function(mid) {
-  function(x) {
-    scale_midpoint(x, midpoint = mid)
+  function(x, to = c(0, 1), from = range(x, na.rm = TRUE)) {
+    scale_midpoint(x, to = to, from = from, midpoint = mid)
   }
 }
diff --git a/man/scale_picker.Rd b/man/scale_picker.Rd
index 7f0f209..c79dadb 100644
--- a/man/scale_picker.Rd
+++ b/man/scale_picker.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/ggplot2.R
+% Please edit documentation in R/scale_colour_picker.R
 \name{scale_picker}
 \alias{scale_picker}
 \alias{scale_colour_picker}
@@ -45,4 +45,4 @@ ggplot2::ggplot(mpg, ggplot2::aes(displ, hwy, colour = class)) +
 \author{
 N. Frerebeau
 }
-\concept{color scales}
+\concept{ggplot2 scales}