--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -12461,6 +12461,8 @@
   type: RelaxedAtomicBool
 #if defined(MOZ_AV1)
   value: true
+#else
+  value: false
 #endif
   mirror: always