diff --git a/waterfox/browser/app/profile/01-theme.js b/waterfox/browser/app/profile/01-theme.js
index b697baf4a3f40..873d5c01667c5 100644
--- a/waterfox/browser/app/profile/01-theme.js
+++ b/waterfox/browser/app/profile/01-theme.js
@@ -7,7 +7,6 @@
 
 pref("browser.theme.enableWaterfoxCustomizations", 1);
 pref("browser.uidensity", 1);
-pref("extensions.activeThemeID", "default-theme@mozilla.org");
 
 // ** Theme Related Options ****************************************************
 // == Theme Distribution Settings ==============================================
diff --git a/waterfox/browser/components/WaterfoxGlue.sys.mjs b/waterfox/browser/components/WaterfoxGlue.sys.mjs
index 24923d0fe9f0f..7b464d232a920 100644
--- a/waterfox/browser/components/WaterfoxGlue.sys.mjs
+++ b/waterfox/browser/components/WaterfoxGlue.sys.mjs
@@ -305,9 +305,10 @@ export const WaterfoxGlue = {
 
     if (!Services.prefs.prefHasUserValue("browser.migration.waterfox_version")) {
       // This is a new profile, nothing to migrate.
-      waterfoxUIVersion.prefs.setIntPref("browser.migration.waterfox_version", waterfoxUIVersion);
+      Services.prefs.setIntPref("browser.migration.waterfox_version", waterfoxUIVersion);
       return;
     }
+    
     async function enableTheme(id) {
       const addon = await lazy.AddonManager.getAddonByID(id);
       // If we found it, enable it.
diff --git a/waterfox/browser/components/uicustomizations/UICustomizations.sys.mjs b/waterfox/browser/components/uicustomizations/UICustomizations.sys.mjs
index c97a6e6537ad0..aea9a7262bda6 100644
--- a/waterfox/browser/components/uicustomizations/UICustomizations.sys.mjs
+++ b/waterfox/browser/components/uicustomizations/UICustomizations.sys.mjs
@@ -11,9 +11,6 @@ import { BrowserUtils } from "resource:///modules/BrowserUtils.sys.mjs";
 export const UICustomizations = {
   PREF_TOOLBARPOS: "browser.tabs.toolbarposition",
   PREF_BOOKMARKPOS: "browser.bookmarks.toolbarposition",
-  PREF_DEFAULTTHEME: "browser.lepton.enabled",
-  PREF_ACTIVETHEME: "extensions.activeThemeID",
-  DEFAULT_THEMEID: "lepton@waterfox.net",
 
   init(window) {
     this.styleButtonBox(window.document);
@@ -22,15 +19,6 @@ export const UICustomizations = {
     this.moveBookmarksBar(window);
     this.initListeners(window);
     this.initPrefObservers();
-
-    // Make sure pref is aligned with active theme ID initially
-    let activeTheme = PrefUtils.get(this.PREF_ACTIVETHEME);
-    if (
-      activeTheme != this.DEFAULT_THEMEID &&
-      PrefUtils.get(this.PREF_DEFAULTTHEME)
-    ) {
-      this.setDefaultThemePref(activeTheme);
-    }
   },
 
   initPrefObservers() {
@@ -55,17 +43,6 @@ export const UICustomizations = {
       }
     );
 
-    // If activeThemeID changes update default theme pref -> could expand to do more than just default or not
-    PrefUtils.addObserver(this.PREF_ACTIVETHEME, value => {
-      this.setDefaultThemePref(value);
-    });
-  },
-
-  setDefaultThemePref(prefValue) {
-    PrefUtils.set(
-      this.PREF_DEFAULTTHEME,
-      prefValue === this.DEFAULT_THEMEID // Currently, only lepton displays icons
-    );
   },
 
   initListeners(aWindow) {