--- a/browser/extensions/e10srollout/bootstrap.js
+++ b/browser/extensions/e10srollout/bootstrap.js
@@ -92,25 +92,20 @@ function defineCohort() {
     setCohort("unsupportedChannel");
     return;
   }
 
   let addonPolicy = "unknown";
   if (updateChannel in ADDON_ROLLOUT_POLICY) {
     addonPolicy = ADDON_ROLLOUT_POLICY[updateChannel];
     Preferences.set(PREF_E10S_ADDON_POLICY, addonPolicy);
+
     // This is also the proper place to set the blocklist pref
     // in case it is necessary.
-
-    Preferences.set(PREF_E10S_ADDON_BLOCKLIST,
-                    // bug 1185672 - Tab Mix Plus
-                    "{dc572301-7619-498c-a57d-39143191b318};"
-                    // bug 1344345 - Mega
-                    + "firefox@mega.co.nz"
-                    );
+    Preferences.set(PREF_E10S_ADDON_BLOCKLIST, "");
   } else {
     Preferences.reset(PREF_E10S_ADDON_POLICY);
   }
 
   let userOptedOut = optedOut();
   let userOptedIn = optedIn();
   let disqualified = (Services.appinfo.multiprocessBlockPolicy != 0);
   let testThreshold = TEST_THRESHOLD[updateChannel];