diff --git a/firefox.js b/firefox.js
index c938306..e23c8ac 100644
--- a/firefox.js
+++ b/firefox.js
@@ -42,6 +42,9 @@ user_pref("browser.tabs.allowTabDetach", false);
 user_pref("full-screen-api.warning.timeout", 0);
 user_pref("full-screen-api.transition.timeout", 0);
 
+// Don't autoplay videos (even without audio)
+user_pref("media.autoplay.default", 5);
+
 // Remove some annoying animations (notably when going full screen)
 user_pref("toolkit.cosmeticAnimations.enabled", false);