diff --git a/assets/prefs.js b/assets/prefs.js
index 07a6263..22e6926 100644
--- a/assets/prefs.js
+++ b/assets/prefs.js
@@ -1,3 +1,7 @@
+// make sure pref file settings are locked
+lockPref("general.config.filename", "prefs.js");
+lockPref("general.config.obscure_value", 0);
+
 // misc
 lockPref("browser.newtabpage.enabled", false);
 lockPref("browser.startup.homepage", "about:blank");
diff --git a/patches/0014-pref-loader.patch b/patches/0014-pref-loader.patch
index f1ec2ae..23b79b0 100644
--- a/patches/0014-pref-loader.patch
+++ b/patches/0014-pref-loader.patch
@@ -1,16 +1,14 @@
 diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
-index 3fce1d2ecf152..5ff02ba2ec2d1 100644
+index 3fce1d2ecf152..ab02e83226dc0 100644
 --- a/modules/libpref/init/all.js
 +++ b/modules/libpref/init/all.js
-@@ -75,7 +75,10 @@ pref("security.crash_tracking.js_load_1.maxCrashes", 1);
+@@ -75,7 +75,8 @@ pref("security.crash_tracking.js_load_1.maxCrashes", 1);
  
  pref("general.useragent.compatMode.firefox", false);
  
 -pref("general.config.obscure_value", 13); // for MCD .cfg files
 +pref("general.config.filename", "prefs.js");
 +pref("general.config.obscure_value", 0);
-+lockPref("general.config.filename", "prefs.js");
-+lockPref("general.config.obscure_value", 0);
  
  #ifndef MOZ_BUILD_APP_IS_BROWSER
  pref("general.warnOnAboutConfig", true);