diff --git a/contrib/python3-whitelist b/contrib/python3-whitelist
--- a/contrib/python3-whitelist
+++ b/contrib/python3-whitelist
@@ -105,6 +105,7 @@
 test-copy-move-merge.t
 test-copy.t
 test-copytrace-heuristics.t
+test-custom-filters.t
 test-debugbuilddag.t
 test-debugbundle.t
 test-debugcommands.t
diff --git a/tests/test-custom-filters.t b/tests/test-custom-filters.t
--- a/tests/test-custom-filters.t
+++ b/tests/test-custom-filters.t
@@ -52,6 +52,7 @@
   $ echo "Very very carefully." >> stuff.txt
   $ hg stat
   M stuff.txt
+  ? __pycache__/prefix.cpython-3*.pyc (glob) (py3k !)
 
   $ echo "Unauthorized material subject to destruction." > morestuff.txt
 
@@ -64,3 +65,4 @@
   $ hg stat
   M stuff.txt
   A morestuff.txt
+  ? __pycache__/prefix.cpython-3*.pyc (glob) (py3k !)