diff --git a/discovery/backends.go b/discovery/backends.go
index f150115..65364c9 100644
--- a/discovery/backends.go
+++ b/discovery/backends.go
@@ -89,7 +89,7 @@ func ParseAdvertise(advertise string) (string, error) {
 		return "", fmt.Errorf("couldnt find a valid ip-address in interface %s", advertise)
 	}
 
-	addr = fmt.Sprintf("%s:%s", addr, port)
+	addr = net.JoinHostPort(addr, port)
 	return addr, nil
 }