diff -r 8b94f05ab069 -r 7d096e5a5b90 mercurial/localrepo.py
--- a/mercurial/localrepo.py	Thu Jan 14 00:56:27 2021 +0100
+++ b/mercurial/localrepo.py	Wed Jan 13 23:51:12 2021 +0100
@@ -1045,7 +1045,7 @@
         options[b'rust.index'] = True
     if requirementsmod.NODEMAP_REQUIREMENT in requirements:
         options[b'persistent-nodemap'] = True
-    if ui.configbool(b'storage', b'revlog.nodemap.mmap'):
+    if ui.configbool(b'storage', b'revlog.persistent-nodemap.mmap'):
         options[b'persistent-nodemap.mmap'] = True
     epnm = ui.config(b'storage', b'revlog.nodemap.mode')
     options[b'persistent-nodemap.mode'] = epnm