diff --git a/lib/base64.c b/lib/base64.c
index 3b36fd0b97..4f48cc0b84 100644
--- a/lib/base64.c
+++ b/lib/base64.c
@@ -42,7 +42,7 @@
 
 #include "base64.h"
 
-#ifdef MALLOCDEBUG
+#ifdef CURLDEBUG
 #include "memdebug.h"
 #endif