diff --git a/Mac/Modules/macmodule.c b/Mac/Modules/macmodule.c
index fbb408b5b7c..f2ffc41b55b 100644
--- a/Mac/Modules/macmodule.c
+++ b/Mac/Modules/macmodule.c
@@ -49,6 +49,10 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <fcntl.h>
 #endif
 
+#ifdef __MWERKS__
+#define MALLOC_DEBUG
+#endif
+
 #include "macdefs.h"
 #include "dirent.h"