Added #include <string.h> for memcpy()
diff --git a/Mac/Modules/res/Resmodule.c b/Mac/Modules/res/Resmodule.c
index dd5d75a..e903158 100644
--- a/Mac/Modules/res/Resmodule.c
+++ b/Mac/Modules/res/Resmodule.c
@@ -43,6 +43,7 @@
 extern PyObject *WinObj_WhichWindow(WindowPtr);
 
 #include <Resources.h>
+#include <string.h>
 
 #define resNotFound -192 /* Can't include <Errors.h> because of Python's "errors.h" */