diff --git a/C/alloc.c b/C/alloc.c
index 4b136df73..28a5d48fd 100755
--- a/C/alloc.c
+++ b/C/alloc.c
@@ -809,7 +809,7 @@ Yap_AllocCodeSpace(unsigned long int size)
 
 #if defined(_WIN32) || defined(__CYGWIN__)
 
-#define DEBUG_WIN32_ALLOC 1
+#undef DEBUG_WIN32_ALLO
 
 #include "windows.h"