diff --git a/src/_imagingcms.c b/src/_imagingcms.c
index 1823bcf03..f152fadbf 100644
--- a/src/_imagingcms.c
+++ b/src/_imagingcms.c
@@ -620,12 +620,6 @@ 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];
diff --git a/src/display.c b/src/display.c
index b4e2e3899..f6380dff3 100644
--- a/src/display.c
+++ b/src/display.c
@@ -34,12 +34,6 @@
 
 #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;
diff --git a/src/libImaging/Dib.c b/src/libImaging/Dib.c
index c69e9e552..a34fba85a 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 f1c8ffcff..5c61e0e7e 100644
--- a/src/libImaging/Draw.c
+++ b/src/libImaging/Draw.c
@@ -35,7 +35,6 @@
 #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/ImDib.h b/src/libImaging/ImDib.h
index e188ffc8e..a0c2348fd 100644
--- a/src/libImaging/ImDib.h
+++ b/src/libImaging/ImDib.h
@@ -12,8 +12,6 @@
 
 #ifdef _WIN32
 
-#include "ImagingPlatform.h"
-
 #if defined(__cplusplus)
 extern "C" {
 #endif
diff --git a/src/libImaging/ImagingPlatform.h b/src/libImaging/ImagingPlatform.h
index c9b7e43b4..78d27067c 100644
--- a/src/libImaging/ImagingPlatform.h
+++ b/src/libImaging/ImagingPlatform.h
@@ -8,7 +8,7 @@
  */
 
 #define PY_SSIZE_T_CLEAN
-#include "Python.h"
+#include <Python.h>
 
 /* Check that we have an ANSI compliant compiler */
 #ifndef HAVE_PROTOTYPES
@@ -18,34 +18,25 @@
 #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
+#endif /* _WIN32 */
+
+/* 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. */
-
-#if __STDC_VERSION__ >= 199901L /* C99+ */
-
 #include <stdint.h>
 
 #define INT8 int8_t
@@ -55,45 +46,11 @@
 #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/QuantOctree.c b/src/libImaging/QuantOctree.c
index ef1a35970..b7ade3102 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 {
diff --git a/src/libImaging/QuantTypes.h b/src/libImaging/QuantTypes.h
index 986b70806..e01023de7 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 {