diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
index e623898b80f5d9e3dc0eece9798a9096e25ec9c0_bWVyY3VyaWFsL29ic29sZXRlLnB5..e69a199bb1274c37aa5a856660f7b34ab31143c6_bWVyY3VyaWFsL29ic29sZXRlLnB5 100644
--- a/mercurial/obsolete.py
+++ b/mercurial/obsolete.py
@@ -210,7 +210,7 @@
 
 # mapping to read/write various marker formats
 # <version> -> (decoder, encoder)
-formats = {0: (_fm0readmarkers, _fm0encodeonemarker)}
+formats = {_fm0version: (_fm0readmarkers, _fm0encodeonemarker)}
 
 def _readmarkers(data):
     """Read and enumerate markers from raw data"""