diff --git a/mode-button.rsc b/mode-button.rsc
index edc5f400..411bc4d2 100644
--- a/mode-button.rsc
+++ b/mode-button.rsc
@@ -10,7 +10,8 @@
 # https://rsc.eworm.de/doc/mode-button.md
 
 :global GlobalFunctionsReady;
-:while ($GlobalFunctionsReady != true) do={ :delay 500ms; }
+:onerror e { :retry { :if ($GlobalFunctionsReady != true) \
+  do={ :error "Global functions not ready."; }; } delay=500ms max=20; } do={ :log error $e; };
 
 :local ExitOK false;
 :do {