diff --git a/scripts/system/help.js b/scripts/system/help.js
index e29fc59e59..aaeb82721c 100644
--- a/scripts/system/help.js
+++ b/scripts/system/help.js
@@ -40,7 +40,7 @@
     }
 
     function onScreenChanged(type, url) {
-        onHelpScreen = type === "Web" && url.startsWith(HELP_URL);
+        onHelpScreen = type === "Web" && (url.indexOf(HELP_URL) === 0);
         button.editProperties({ isActive: onHelpScreen });
     }