diff --git a/src/cc20.c b/src/cc20.c
index 24cbc87..2dd2bb0 100644
--- a/src/cc20.c
+++ b/src/cc20.c
@@ -375,6 +375,8 @@ int cc20_crypt (unsigned char *out, const unsigned char *in, size_t in_len,
       in_len--;
     }
   }
+
+  return(0);
 }