diff -r 47ccab19bf9f -r acd84c434896 mercurial/hgweb/server.py
--- a/mercurial/hgweb/server.py	Mon May 10 21:59:13 2021 +0200
+++ b/mercurial/hgweb/server.py	Sat May 15 09:45:10 2021 +0000
@@ -344,7 +344,7 @@
 try:
     import threading
 
-    threading.activeCount()  # silence pyflakes and bypass demandimport
+    threading.active_count()  # silence pyflakes and bypass demandimport
     _mixin = socketserver.ThreadingMixIn
 except ImportError:
     if util.safehasattr(os, b"fork"):