diff --git a/Modules/_codecsmodule.c b/Modules/_codecsmodule.c
index 61e5516..727cf5e 100644
--- a/Modules/_codecsmodule.c
+++ b/Modules/_codecsmodule.c
@@ -38,6 +38,10 @@
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
 
+#ifdef MS_WINDOWS
+#include <windows.h>
+#endif
+
 /* --- Registry ----------------------------------------------------------- */
 
 PyDoc_STRVAR(register__doc__,