diff --git a/mercurial/statprof.py b/mercurial/statprof.py
--- a/mercurial/statprof.py
+++ b/mercurial/statprof.py
@@ -352,7 +352,7 @@
             frame = inspect.currentframe()
             tid = [k for k, f in sys._current_frames().items() if f == frame][0]
             state.thread = threading.Thread(
-                target=samplerthread, args=(tid,), name=b"samplerthread"
+                target=samplerthread, args=(tid,), name="samplerthread"
             )
             state.thread.start()