diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index b2c3c5f30bff..47afa562d03a 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -73,6 +73,9 @@ pref("xpinstall.signatures.devInfoURL", "https://wiki.mozilla.org/Addons/Extensi
 // Enable extensionStorage storage actor by default
 pref("devtools.storage.extensionStorage.enabled", true);
 
+// Enable the unified extensions UI by default.
+pref("extensions.unifiedExtensions.enabled", true);
+
 // Dictionary download preference
 pref("browser.dictionaries.download.url", "https://addons.mozilla.org/%LOCALE%/firefox/language-tools/");
 
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index a7e0c765115d..e58f15e07d6e 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1954,12 +1954,9 @@ pref("extensions.eventPages.enabled", true);
 pref("extensions.manifestV2.actionsPopupURLRestricted", false);
 // Whether "manifest_version: 3" extensions should be allowed to install successfully.
 pref("extensions.manifestV3.enabled", true);
-// Whether to enable the unified extensions feature.
-#ifdef NIGHTLY_BUILD
-  pref("extensions.unifiedExtensions.enabled", true);
-#else
-  pref("extensions.unifiedExtensions.enabled", false);
-#endif
+// Whether to enable the unified extensions feature. Note that this pref is
+// enabled for Firefox Desktop in `browser/app/profile/firefox.js`.
+pref("extensions.unifiedExtensions.enabled", false);
 // Whether to enable the updated openPopup API.
 #ifdef NIGHTLY_BUILD
   pref("extensions.openPopupWithoutUserGesture.enabled", true);