diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 3b9fd05..39beaba 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -326,6 +326,8 @@
 
 /* choose the appropriate stat and fstat functions and return structs */
 #undef STAT
+#undef FSTAT
+#undef STRUCT_STAT
 #if defined(MS_WIN64) || defined(MS_WINDOWS)
 #       define STAT win32_stat
 #       define FSTAT win32_fstat