diff --git a/mercurial/vfs.py b/mercurial/vfs.py
--- a/mercurial/vfs.py
+++ b/mercurial/vfs.py
@@ -486,7 +486,9 @@
             threading.currentThread(),
             threading._MainThread,  # pytype: disable=module-attr
         ):
-            if not self._backgroundfilecloser:
+            if (
+                not self._backgroundfilecloser
+            ):  # pytype: disable=attribute-error
                 raise error.Abort(
                     _(
                         b'backgroundclose can only be used when a '
@@ -494,7 +496,9 @@
                     )
                 )
 
-            fp = delayclosedfile(fp, self._backgroundfilecloser)
+            fp = delayclosedfile(
+                fp, self._backgroundfilecloser
+            )  # pytype: disable=attribute-error
 
         return fp