diff --git a/cmd/syncthing/upnpsvc.go b/cmd/syncthing/upnpsvc.go
index df71a69bd..52f98cd19 100644
--- a/cmd/syncthing/upnpsvc.go
+++ b/cmd/syncthing/upnpsvc.go
@@ -100,7 +100,7 @@ func (s *upnpSvc) tryIGD(igd upnp.IGD, suggestedPort int) (int, error) {
 	for i := 0; i < 10; i++ {
 		// Then try up to ten random ports.
 		extPort := 1024 + predictableRandom.Intn(65535-1024)
-		name := fmt.Sprintf("syncthing-%d", suggestedPort)
+		name := fmt.Sprintf("syncthing-%d", extPort)
 		err = igd.AddPortMapping(upnp.TCP, extPort, s.localPort, name, leaseTime)
 		if err == nil {
 			return extPort, nil