diff --git a/generic/tkColor.c b/generic/tkColor.c
index b23255e64..baff5e794 100644
--- a/generic/tkColor.c
+++ b/generic/tkColor.c
@@ -62,7 +62,7 @@ const TkObjType tkColorObjType = {
     DupColorObjProc,		/* dupIntRepProc */
     NULL,			/* updateStringProc */
     NULL,			/* setFromAnyProc */
-    TCL_OBJTYPE_V0},
+    TCL_OBJTYPE_V1(TkLengthOne)},
     0
 };
 
diff --git a/generic/tkCursor.c b/generic/tkCursor.c
index 97854708d..1bed0c4a9 100644
--- a/generic/tkCursor.c
+++ b/generic/tkCursor.c
@@ -65,7 +65,7 @@ const TkObjType tkCursorObjType = {
     DupCursorObjProc,		/* dupIntRepProc */
     NULL,			/* updateStringProc */
     NULL,			/* setFromAnyProc */
-    TCL_OBJTYPE_V0},
+    TCL_OBJTYPE_V1(TkLengthOne)},
     0
 };
 
diff --git a/generic/tkInt.h b/generic/tkInt.h
index dc2347c28..5ee47915e 100644
--- a/generic/tkInt.h
+++ b/generic/tkInt.h
@@ -1138,6 +1138,9 @@ typedef struct {
 #ifndef TCL_OBJTYPE_V0
 #   define TCL_OBJTYPE_V0 /* just empty */
 #endif
+#ifndef TCL_OBJTYPE_V1
+#   define TCL_OBJTYPE_V1(lengthProc) /* just empty */
+#endif
 
 MODULE_SCOPE const TkObjType tkBorderObjType;
 MODULE_SCOPE const TkObjType tkBitmapObjType;
@@ -1330,6 +1333,7 @@ MODULE_SCOPE void	TkpDrawFrameEx(Tk_Window tkwin, Drawable drawable,
 			    int borderWidth, int relief);
 MODULE_SCOPE void	TkpShowBusyWindow(TkBusy busy);
 MODULE_SCOPE void	TkpHideBusyWindow(TkBusy busy);
+MODULE_SCOPE Tcl_Size	TkLengthOne(Tcl_Obj *);
 MODULE_SCOPE void	TkpMakeTransparentWindowExist(Tk_Window tkwin,
 			    Window parent);
 MODULE_SCOPE void	TkpCreateBusy(Tk_FakeWin *winPtr, Tk_Window tkRef,
diff --git a/generic/tkObj.c b/generic/tkObj.c
index 2eadff33c..170f7d08c 100644
--- a/generic/tkObj.c
+++ b/generic/tkObj.c
@@ -137,10 +137,17 @@ static const TkObjType pixelObjType = {
     DupPixelInternalRep,	/* dupIntRepProc */
     NULL,			/* updateStringProc */
     NULL,			/* setFromAnyProc */
-    TCL_OBJTYPE_V0},
+    TCL_OBJTYPE_V1(TkLengthOne)},
     0
 };
 
+Tcl_Size
+TkLengthOne(
+    TCL_UNUSED(Tcl_Obj *))
+{
+    return 1;
+}
+
 /*
  * The following structure defines the implementation of the "pixel" Tcl
  * object, used for measuring distances. The pixel object remembers its
@@ -153,7 +160,7 @@ static const TkObjType mmObjType = {
     DupMMInternalRep,		/* dupIntRepProc */
     UpdateStringOfMM,		/* updateStringProc */
     NULL,			/* setFromAnyProc */
-    TCL_OBJTYPE_V0},
+    TCL_OBJTYPE_V1(TkLengthOne)},
     0
 };