diff --git a/addons/51degrees/dummy/v4hash/hash/hash.h b/addons/51degrees/dummy/v4hash/hash/hash.h
index 5d04d1766..5b114d26c 100644
--- a/addons/51degrees/dummy/v4hash/hash/hash.h
+++ b/addons/51degrees/dummy/v4hash/hash/hash.h
@@ -40,8 +40,7 @@
 #include <stdlib.h>
 #include <inttypes.h>
 
-typedef int bool;
-enum { false, true };
+#include <stdbool.h>
 
 typedef unsigned char byte;