diff --git a/update-tunnelbroker.rsc b/update-tunnelbroker.rsc
index 10adef0..2deb5b2 100644
--- a/update-tunnelbroker.rsc
+++ b/update-tunnelbroker.rsc
@@ -11,11 +11,11 @@
 # update local address of tunnelbroker interface
 # https://rsc.eworm.de/doc/update-tunnelbroker.md
 
-:global GlobalFunctionsReady;
-:while ($GlobalFunctionsReady != true) do={ :delay 500ms; }
-
 :local ExitOK false;
 :onerror Err {
+  :global GlobalFunctionsReady;
+  :retry { :if ($GlobalFunctionsReady != true) \
+      do={ :error ("Global functions not ready."); }; } delay=500ms max=50;
   :local ScriptName [ :jobname ];
 
   :global CertificateAvailable;