diff --git a/testing/talos/talos/base_profile/prefs.js b/testing/talos/talos/base_profile/prefs.js
deleted file mode 100755
index 6c2922f6aa2d..000000000000
--- a/testing/talos/talos/base_profile/prefs.js
+++ /dev/null
@@ -1,12 +0,0 @@
-// This file is needed to work around a Firefox bug where capability.principal
-// prefs in user.js don't get recognized until the second browser launch
-// which is too late for our purposes of using quit.js. Loading the principals
-// from prefs.js avoids this issue.
-/* globals user_pref */
-user_pref("capability.principal.codebase.p0.granted", "UniversalPreferencesWrite UniversalXPConnect UniversalPreferencesRead");
-user_pref("capability.principal.codebase.p0.id", "file://");
-user_pref("capability.principal.codebase.p0.subjectName", "");
-user_pref("capability.principal.codebase.p1.granted", "UniversalPreferencesWrite UniversalXPConnect UniversalPreferencesRead");
-user_pref("capability.principal.codebase.p1.id", "http://localhost");
-user_pref("capability.principal.codebase.p1.subjectName", "");
-user_pref("signed.applets.codebase_principal_support", true);
diff --git a/testing/talos/talos/tests/quit.js b/testing/talos/talos/tests/quit.js
index 34c5aa51a81c..61ad1a3e0e4f 100644
--- a/testing/talos/talos/tests/quit.js
+++ b/testing/talos/talos/tests/quit.js
@@ -63,12 +63,9 @@ function canQuitApplication() {
 }
 
 function goQuitApplication(waitForSafeBrowsing) {
-  const privs = "UniversalPreferencesRead UniversalPreferencesWrite " +
-    "UniversalXPConnect";
-
   /* eslint-disable mozilla/use-chromeutils-import */
   try {
-    netscape.security.PrivilegeManager.enablePrivilege(privs);
+    netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
   } catch (ex) {
     throw ("goQuitApplication: privilege failure " + ex);
   }