--- a/browser/base/content/test/plugins/browser_pluginnotification.js
+++ b/browser/base/content/test/plugins/browser_pluginnotification.js
@@ -56,16 +56,19 @@ TabOpenListener.prototype = {
 
 function test() {
   waitForExplicitFinish();
   SimpleTest.requestCompleteLog();
   requestLongerTimeout(2);
   registerCleanupFunction(function() {
     clearAllPluginPermissions();
     Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
+    return new Promise(resolve => {
+      setAndUpdateBlocklist(gHttpTestRoot + "blockNoPlugins.xml", resolve);
+    });
   });
   Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
 
   setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
   setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY, "Second Test Plug-in");
 
   var newTab = gBrowser.addTab();
   gBrowser.selectedTab = newTab;