diff --git a/Implementierung/lib/md2_impls/md2_reference/md2_reference.h b/Implementierung/lib/md2_impls/md2_reference/md2_reference.h
index 4d60e09..6da77de 100644
--- a/Implementierung/lib/md2_impls/md2_reference/md2_reference.h
+++ b/Implementierung/lib/md2_impls/md2_reference/md2_reference.h
@@ -15,6 +15,8 @@
 #include <string.h>
 #include <sys/types.h>
 
+#include "../md2_common.h"
+
 #ifndef PROTOTYPES
 #define PROTOTYPES 0
 #endif