--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -69,16 +69,19 @@ pref("extensions.screenshots.system-disa
 // Disable add-ons that are not installed by the user in all scopes by default.
 // See the SCOPE constants in AddonManager.jsm for values to use here.
 pref("extensions.autoDisableScopes", 15);
 
 // Add-on content security policies.
 pref("extensions.webextensions.base-content-security-policy", "script-src 'self' https://* moz-extension: blob: filesystem: 'unsafe-eval' 'unsafe-inline'; object-src 'self' https://* moz-extension: blob: filesystem:;");
 pref("extensions.webextensions.default-content-security-policy", "script-src 'self'; object-src 'self';");
 
+// Extensions that should not be flagged as legacy in about:addons
+pref("extensions.legacy.exceptions", "{972ce4c6-7e08-4474-a285-3208198ce6fd},testpilot@cliqz.com,@testpilot-containers,jid1-NeEaf3sAHdKHPA@jetpack,@activity-streams,pulse@mozilla.com,@testpilot-addon,@min-vid,tabcentertest1@mozilla.com,snoozetabs@mozilla.com,speaktome@mozilla.com,hoverpad@mozilla.com");
+
 // Require signed add-ons by default
 pref("xpinstall.signatures.required", true);
 pref("xpinstall.signatures.devInfoURL", "https://wiki.mozilla.org/Addons/Extension_Signing");
 
 // Dictionary download preference
 pref("browser.dictionaries.download.url", "https://addons.mozilla.org/%LOCALE%/firefox/dictionaries/");
 
 // At startup, should we check to see if the installation