diff --git a/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/Session.java b/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/Session.java
index 292e4fda2..3c4d2ae3d 100644
--- a/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/Session.java
+++ b/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/Session.java
@@ -42,6 +42,7 @@
 import org.mozilla.vrbrowser.telemetry.TelemetryWrapper;
 import org.mozilla.vrbrowser.utils.BitmapCache;
 import org.mozilla.vrbrowser.utils.InternalPages;
+import org.mozilla.vrbrowser.utils.StringUtils;
 import org.mozilla.vrbrowser.utils.SystemUtils;
 
 import java.net.URI;
@@ -870,12 +871,6 @@ public void onCanGoForward(@NonNull GeckoSession aSession, boolean aCanGoForward
 
         Log.d(LOGTAG, "onLoadRequest: " + uri);
 
-        String uriOverride = SessionUtils.checkYoutubeOverride(uri);
-        if (uriOverride != null) {
-            aSession.loadUri(uriOverride);
-            return GeckoResult.DENY;
-        }
-
         if (aSession == mState.mSession) {
             Log.d(LOGTAG, "Testing for UA override");
 
diff --git a/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/SessionUtils.java b/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/SessionUtils.java
index 11ac4bf99..62694a5eb 100644
--- a/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/SessionUtils.java
+++ b/app/src/common/shared/org/mozilla/vrbrowser/browser/engine/SessionUtils.java
@@ -69,48 +69,4 @@ private static void addOptionalPref(FileOutputStream out, String aKey, Bundle aE
             out.write(String.format("pref(\"%s\", %s);\n", aKey, value ? "true" : "false").getBytes());
         }
     }
-
-    /**
-     * 1. Disable YouTube's Polymer layout (which makes YouTube very slow in non-Chrome browsers)
-     *    via a query-string parameter in the URL.
-     * 2. Rewrite YouTube URLs from `m.youtube.com` -> `youtube.com` (to avoid serving YouTube's
-     *    video pages intended for mobile phones, as linked from Google search results).
-     */
-    public static String checkYoutubeOverride(String aUri) {
-        try {
-            Uri uri = Uri.parse(aUri);
-            String hostLower = uri.getHost().toLowerCase();
-            if (!hostLower.endsWith(".youtube.com") && !hostLower.endsWith(".youtube-nocookie.com")) {
-                return null;
-            }
-
-            Uri.Builder uriBuilder = uri.buildUpon();
-            Boolean updateUri = false;
-
-            if (!uri.getScheme().equalsIgnoreCase("https")) {
-                uriBuilder.scheme("https");
-                updateUri = true;
-            }
-            if (hostLower.startsWith("m.")) {
-                uriBuilder.authority(hostLower.replaceFirst("m.", "www."));
-                updateUri = true;
-            }
-            String queryDisablePolymer = uri.getQueryParameter("disable_polymer");
-            if (queryDisablePolymer == null) {
-                uriBuilder.appendQueryParameter("disable_polymer", "1");
-                updateUri = true;
-            }
-
-            if (!updateUri) {
-                return null;
-            }
-
-            return uriBuilder.build().toString();
-        } catch (Exception ex) {
-            Log.e(LOGTAG, "Unable to construct transformed URL: " + ex.toString());
-        }
-
-        return null;
-    }
-
 }
diff --git a/app/src/main/assets/web_extensions/webcompat_youtube/background.js b/app/src/main/assets/web_extensions/webcompat_youtube/background.js
new file mode 100644
index 000000000..99ceae544
--- /dev/null
+++ b/app/src/main/assets/web_extensions/webcompat_youtube/background.js
@@ -0,0 +1,33 @@
+const targetUrls = [
+	"https://*.youtube.com/*",
+	"https://*.youtube-nocookie.com/*"
+];
+
+/**
+ * 1. Disable YouTube's Polymer layout (which makes YouTube very slow in non-Chrome browsers)
+ *    via a query-string parameter in the URL.
+ * 2. Rewrite YouTube URLs from `m.youtube.com` -> `youtube.com` (to avoid serving YouTube's
+ *    video pages intended for mobile phones, as linked from Google search results).
+ */
+function redirectUrl(req) {
+	let redirect = false;
+	const url = new URL(req.url);
+	if (url.host.startsWith("m.")) {
+		url.host = url.host.replace("m.", "www.");
+		redirect = true;
+	}
+	if (!url.searchParams.get("disable_polymer")) {
+		url.searchParams.set("disable_polymer", "1");
+		redirect = true;
+	}
+	if (!redirect) {
+		return null;
+	}
+	return { redirectUrl: url.toString() };
+}
+
+browser.webRequest.onBeforeRequest.addListener(
+	redirectUrl,
+	{ urls: targetUrls, types: ["main_frame"]},
+	["blocking"]
+);
diff --git a/app/src/main/assets/web_extensions/webcompat_youtube/main.js b/app/src/main/assets/web_extensions/webcompat_youtube/main.js
index 8eb2357bc..6d73fc5e3 100644
--- a/app/src/main/assets/web_extensions/webcompat_youtube/main.js
+++ b/app/src/main/assets/web_extensions/webcompat_youtube/main.js
@@ -297,16 +297,6 @@ try {
       window.wrappedJSObject.ytplayer.config.args.jsapicallback = 'onYouTubePlayerReady';
     }
   });
-
-  window.addEventListener("beforeunload", function (e) {
-    // Make sure that the disable_polymer parameter is kept. Youtube processes the parameter but removes it from the URL.
-    // See https://github.com/MozillaReality/FirefoxReality/issues/1426
-    let qs = new URLSearchParams(window.location.search);
-    qs.set('disable_polymer', '1');
-    let url = getNewUrl(qs);
-    window.history.replaceState({}, document.title, url);
-  });
-
 } catch (err) {
   console.error(LOGTAG, 'Encountered error:', err);
 }
diff --git a/app/src/main/assets/web_extensions/webcompat_youtube/manifest.json b/app/src/main/assets/web_extensions/webcompat_youtube/manifest.json
index 9e3daea7d..de4ef82c1 100644
--- a/app/src/main/assets/web_extensions/webcompat_youtube/manifest.json
+++ b/app/src/main/assets/web_extensions/webcompat_youtube/manifest.json
@@ -18,5 +18,10 @@
       "run_at": "document_start",
       "all_frames": true
     }
-  ]
+  ],
+  "permissions": ["webRequest", "webRequestBlocking", "*://*.youtube.com/*", "*://*.youtube-nocookie.com/*"],
+  "background": {
+    "scripts": ["background.js"]
+  }
+
 }