Oh, actually it was my mistake

PRIx64 is defined in <inttypes.h>, not <stdint.h>.

I hate C.

persistent/cPersistence.c

@@ -28,16 +28,13 @@ struct ccobject_head_struct
 /*
   The compiler on Windows used for Python 2.7 doesn't include
   stdint.h.
-  The compiler on Windows used for Python 3.5 doesn't define
-  PRIx64 in its copy of stdint.h.
 */
 #if !defined(PY3K) && defined(_WIN32)
 typedef unsigned long long uint64_t;
+#  define PRIx64 "llx"
 #else
 #  include <stdint.h>
-#endif
-#ifndef PRIx64 && defined(_WIN32)
-#  define PRIx64 "llx"
+#  include <inttypes.h>
 #endif
 
 /* These two objects are initialized when the module is loaded */