diff --git a/models/yang/mano-types.yang b/models/yang/mano-types.yang
index b6350ae..654fcbb 100644
--- a/models/yang/mano-types.yang
+++ b/models/yang/mano-types.yang
@@ -202,7 +202,6 @@
              the same name as entered here.
             ";
       type string;
-      mandatory "true";
     }
 
     leaf image-checksum {