--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -564,16 +564,17 @@ option('--enable-stylo', env='STYLO_ENAB
             'This requires either building servo within Gecko\'s cargo phase '
             'or passing --with-servo')
 
 @depends('--enable-stylo')
 def stylo(value):
     if value:
         return True
 
+set_config('MOZ_STYLO', stylo)
 set_define('MOZ_STYLO', stylo)
 imply_option('--enable-jemalloc', depends_if('--enable-stylo')(lambda _: 'moz'))
 
 option('--with-servo', env='SERVO_TARGET_DIR', nargs=1,
        help='Absolute path of the target directory where libgeckoservo can '
             'be found. This is generally servo_src_dir/target/release.')
 
 @depends_if('--with-servo')