diff --git a/src/marionette.rs b/src/marionette.rs
index 4a517f1e..5693e1e8 100644
--- a/src/marionette.rs
+++ b/src/marionette.rs
@@ -351,8 +351,6 @@ impl MarionetteHandler {
 
         prefs.insert_slice(&extra_prefs[..]);
 
-        prefs.insert_slice(&prefs::REQUIRED[..]);
-
         if let Some(ref level) = self.current_log_level {
             prefs.insert("marionette.logging", Pref::new(level.to_string()));
         };
diff --git a/src/prefs.rs b/src/prefs.rs
index 4bee6aa7..3e828504 100644
--- a/src/prefs.rs
+++ b/src/prefs.rs
@@ -1,7 +1,7 @@
 use mozprofile::preferences::Pref;
 
 lazy_static! {
-    pub static ref DEFAULT: [(&'static str, Pref); 75] = [
+    pub static ref DEFAULT: [(&'static str, Pref); 78] = [
         // Disable automatic downloading of new releases
         ("app.update.auto", Pref::new(false)),
 
@@ -65,6 +65,9 @@ lazy_static! {
         // Skip check for default browser on startup
         ("browser.shell.checkDefaultBrowser", Pref::new(false)),
 
+        // Do not warn when quitting with multiple tabs
+        ("browser.showQuitWarning", Pref::new(false)),
+
         // Disable Android snippets
         ("browser.snippets.enabled", Pref::new(false)),
         ("browser.snippets.syncPromo.enabled", Pref::new(false)),
@@ -88,6 +91,9 @@ lazy_static! {
         // might get unloaded
         ("browser.tabs.disableBackgroundZombification", Pref::new(false)),
 
+        // Do not warn on exit when multiple tabs are open
+        ("browser.tabs.warnOnClose", Pref::new(false)),
+
         // Do not warn when closing all other open tabs
         ("browser.tabs.warnOnCloseOtherTabs", Pref::new(false)),
 
@@ -100,6 +106,9 @@ lazy_static! {
         // Disable the UI tour
         ("browser.uitour.enabled", Pref::new(false)),
 
+        // Do not warn on quitting Firefox
+        ("browser.warnOnQuit", Pref::new(false)),
+
         // Do not show datareporting policy notifications which can
         // interfere with tests
         ("datareporting.healthreport.about.reportUrl", Pref::new("http://%(server)s/dummy/abouthealthreport/")),
@@ -214,22 +223,4 @@ lazy_static! {
         // We want to collect telemetry, but we don't want to send in the results
         ("toolkit.telemetry.server", Pref::new("https://%(server)s/dummy/telemetry/")),
     ];
-
-    pub static ref REQUIRED: [(&'static str, Pref); 5] = [
-        // Do not warn on quitting Firefox
-        ("browser.warnOnQuit", Pref::new(false)),
-
-        // Do not warn on exit when multiple tabs are open
-        ("browser.tabs.warnOnClose", Pref::new(false)),
-
-        // Do not warn when quitting with multiple tabs
-        ("browser.showQuitWarning", Pref::new(false)),
-
-        // Until bug 1238095 is fixed, we have to disable safe CPOW checks
-        ("dom.ipc.cpows.forbid-unsafe-from-browser", Pref::new(false)),
-
-        // TODO(ato): Should not be needed, as Marionette is enabled by
-        // passing the --marionette flag to the binary
-        ("marionette.defaultPrefs.enabled", Pref::new(true)),
-    ];
 }