diff --git a/tests/test-flagprocessor.t b/tests/test-flagprocessor.t
--- a/tests/test-flagprocessor.t
+++ b/tests/test-flagprocessor.t
@@ -204,7 +204,8 @@
     File "*/mercurial/extensions.py", line *, in _runextsetup (glob)
       extsetup(ui)
     File "*/tests/flagprocessorext.py", line *, in extsetup (glob)
-      REVIDX_NOOP, (noopdonothingread, noopdonothing, validatehash,)
+      flagutil.addflagprocessor( (py38 !)
+      REVIDX_NOOP, (noopdonothingread, noopdonothing, validatehash,) (no-py38 !)
     File "*/mercurial/revlogutils/flagutil.py", line *, in addflagprocessor (glob)
       insertflagprocessor(flag, processor, flagprocessors)
     File "*/mercurial/revlogutils/flagutil.py", line *, in insertflagprocessor (glob)