--- a/include/common-template.inc.php
+++ b/include/common-template.inc.php
@@ -175,7 +175,7 @@
         <div data-role="content"> ';
         if ($GTFSREnabled) {
         $overrides = getServiceOverride();
-        if ($overrides['service_id']) {
+        if (isset($overrides['service_id'])) {
             if ($overrides['service_id'] == "noservice") {
                 echo '<div id="servicewarning">Buses are <strong>not running today</strong> due to industrial action/public holiday. See <a 
 href="http://www.action.act.gov.au">http://www.action.act.gov.au</a> for details.</div>';