diff --git a/xos/synchronizer/models/volt.xproto b/xos/synchronizer/models/volt.xproto
index 60fb08d..927006f 100644
--- a/xos/synchronizer/models/volt.xproto
+++ b/xos/synchronizer/models/volt.xproto
@@ -24,7 +24,7 @@
     optional string name = 2 [help_text = "name of device", max_length = 254, db_index = False, unique = True];
     required string device_type = 3 [help_text = "Device Type", default = "openolt", max_length = 254, db_index = False];
     optional string host = 4 [help_text = "Device IP", max_length = 254, db_index = False];
-    optional int32 port = 5 [help_text = "Device port", db_index = False];
+    optional int32 port = 5 [help_text = "Device port", db_index = False, unique_with = "host"];
     optional string mac_address = 6 [help_text = "Device mac address", db_index = False];
 
     optional string serial_number = 9 [help_text = "Serial Number", db_index = False];