diff --git a/background.js b/background.js
index 6b61c29..15761f8 100644
--- a/background.js
+++ b/background.js
@@ -14,7 +14,8 @@ browser.webRequest.onBeforeRequest.addListener(
       }
     }
   },
-  { urls: ["<all_urls>"] },
+  { urls: [  "*://www.youtube.com/*",
+      "*://youtube.com/*"] },
   ["blocking"]
 );