diff --git a/Python/importdl.c b/Python/importdl.c
index 7a0de085a5c..1a994ce15ba 100644
--- a/Python/importdl.c
+++ b/Python/importdl.c
@@ -106,9 +106,14 @@ typedef int (* APIENTRY dl_funcptr)();
 #include <windows.h>
 typedef FARPROC dl_funcptr;
 #define _DL_FUNCPTR_DEFINED
+#ifdef _DEBUG
+#define SHORT_EXT "_d.pyd"
+#define LONG_EXT "_d.dll"
+#else
 #define SHORT_EXT ".pyd"
 #define LONG_EXT ".dll"
 #endif
+#endif
 
 #ifdef NeXT
 #define DYNAMIC_LINK