--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -409,17 +409,17 @@ imply_option('--enable-fmp4', ffmpeg, '-
 # ==============================================================
 option('--enable-av1',
         help='Enable libaom for av1 video support')
 
 @depends('--enable-av1', target, milestone)
 def av1(value, target, milestone):
     enabled = bool(value)
     if value.origin == 'default' and milestone.is_nightly:
-        enabled = target.os not in ('Android', 'WINNT')
+        enabled = target.os != 'Android'
     if enabled:
         return True
 
 set_config('MOZ_AV1', av1)
 set_define('MOZ_AV1', av1)
 
 # Built-in fragmented MP4 support.
 # ==============================================================