diff --git a/user.js b/user.js
index 600d505..0215d79 100644
--- a/user.js
+++ b/user.js
@@ -1692,6 +1692,7 @@ user_pref("browser.bookmarks.showRecentlyBookmarked", false);
    // user_pref("media.wave.enabled", false);
    // user_pref("media.webm.enabled", false);
    // user_pref("media.wmf.enabled", false); // https://www.youtube.com/html5 - for the two H.264 entries
+   // user_pref("media.wmf.vp9.enabled", false);
 /* 3026: disable "Reader View" ***/
    // user_pref("reader.parse-on-load.enabled", false);
 /* 3027: decode URLs on copy from the urlbar (FF53+)