cast return type to enum
diff --git a/signkey.c b/signkey.c
index 55f34e7..a043d0d 100644
--- a/signkey.c
+++ b/signkey.c
@@ -93,7 +93,7 @@
 			}
 #endif
 
-			return i;
+			return (enum signkey_type)i;
 		}
 	}