diff --git a/src/config/api-server/vnc_cfg_types.py b/src/config/api-server/vnc_cfg_types.py
index 68e02a4b35a..fd1e6c15d8c 100644
--- a/src/config/api-server/vnc_cfg_types.py
+++ b/src/config/api-server/vnc_cfg_types.py
@@ -378,7 +378,7 @@ def http_post_collection(cls, tenant_name, obj_dict, db_conn):
             mc = obj_dict['virtual_machine_interface_mac_addresses']
             if 'mac_address' in mc:
                 if len(mc['mac_address'])==1:
-                    inmac = mc['mac_address']
+                    inmac = [m.replace("-",":") for m in mc['mac_address']]
         if inmac!=None:
             mac_addrs_obj = MacAddressesType(inmac)
         else: