diff -Naur Python-3.7.0-orig/Include/pyport.h Python-3.7.0/Include/pyport.h
--- Python-3.7.0-orig/Include/pyport.h	2018-06-27 06:07:35.000000000 +0300
+++ Python-3.7.0/Include/pyport.h	2018-07-12 10:20:45.523090700 +0300
@@ -5,6 +5,21 @@
 
 #include <inttypes.h>
 
+#ifdef __MINGW32__
+/* Translate GCC[mingw*] platform specific defines to those
+ * used in python code.
+ */
+#if !defined(MS_WIN64) && defined(_WIN64)
+#  define MS_WIN64
+#endif
+#if !defined(MS_WIN32) && defined(_WIN32)
+#  define MS_WIN32
+#endif
+#if !defined(MS_WINDOWS) && defined(MS_WIN32)
+#  define MS_WINDOWS
+#endif
+#endif /* __MINGW32__*/
+
 /**************************************************************************
 Symbols and macros to supply platform-independent interfaces to basic
 C language & library operations whose spellings vary across platforms.