diff --git a/lib/quirc_internal.h b/lib/quirc_internal.h
index ed23319..9eec32a 100644
--- a/lib/quirc_internal.h
+++ b/lib/quirc_internal.h
@@ -17,10 +17,13 @@
 #ifndef QUIRC_INTERNAL_H_
 #define QUIRC_INTERNAL_H_
 
+#include <assert.h>
 #include <stdlib.h>
 
 #include "quirc.h"
 
+#define QUIRC_ASSERT(a)	assert(a)
+
 #define QUIRC_PIXEL_WHITE	0
 #define QUIRC_PIXEL_BLACK	1
 #define QUIRC_PIXEL_REGION	2