diff --git a/browser/components/BrowserGlue.sys.mjs b/browser/components/BrowserGlue.sys.mjs
index b888a753a7f23a9800fe04da51a4e6b898314ff2..35eea774e1ea4b1807ec65ebc767f423d81602bd 100644
--- a/browser/components/BrowserGlue.sys.mjs
+++ b/browser/components/BrowserGlue.sys.mjs
@@ -121,6 +121,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
   WindowsGPOParser: "resource://gre/modules/policies/WindowsGPOParser.sys.mjs",
   clearTimeout: "resource://gre/modules/Timer.sys.mjs",
   setTimeout: "resource://gre/modules/Timer.sys.mjs",
+  gZenUIMigration: "chrome://browser/content/zen-components/ZenUIMigration.mjs",
 });
 
 if (AppConstants.MOZ_UPDATER) {
@@ -1951,6 +1952,7 @@ BrowserGlue.prototype = {
 
     lazy.UrlbarPrefs.updateFirefoxSuggestScenario();
 
+    lazy.gZenUIMigration.init(this._isNewProfile, aWindow);
     // A channel for "remote troubleshooting" code...
     let channel = new lazy.WebChannel(
       "remote-troubleshooting",
@@ -4761,6 +4763,7 @@ BrowserGlue.prototype = {
   },
 
   async _maybeShowDefaultBrowserPrompt() {
+    this._ZenMaybeShowWelcomeScreen();
     // Highest priority is about:welcome window modal experiment
     // Second highest priority is the upgrade dialog, which can include a "primary
     // browser" request and is limited in various ways, e.g., major upgrades.
@@ -5302,6 +5305,16 @@ BrowserGlue.prototype = {
     "nsIObserver",
     "nsISupportsWeakReference",
   ]),
+
+  _ZenMaybeShowWelcomeScreen() {
+    const welcomeEnabled = Services.prefs.getBoolPref("zen.welcome-screen.enabled", true)
+    const welcomeSeen = Services.prefs.getBoolPref("zen.welcome-screen.seen", false)
+    if (welcomeEnabled && !welcomeSeen) {
+      lazy.BrowserWindowTracker.getTopWindow().gDialogBox.open(
+        "chrome://browser/content/zen-welcome/welcome.html"
+      );
+    }
+  },
 };
 
 var ContentBlockingCategoriesPrefs = {