diff --git a/agent/proxycfg/connect_proxy.go b/agent/proxycfg/connect_proxy.go
index 1e244bdff1..416e321ae8 100644
--- a/agent/proxycfg/connect_proxy.go
+++ b/agent/proxycfg/connect_proxy.go
@@ -292,6 +292,8 @@ func (s *handlerConnectProxy) setupWatchesForPeeredUpstream(
 			}
 			snapConnectProxy.WatchedLocalGWEndpoints.InitWatch(gk.String(), nil)
 		}
+	} else if mgwMode == structs.MeshGatewayModeNone {
+		s.logger.Warn(fmt.Sprintf("invalid mesh gateway mode 'none', defaulting to 'remote' for %q", uid))
 	}
 	return nil
 }