diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -12,7 +12,7 @@ from demandload import *
 demandload(globals(), "bisect array")
 
 class manifest(revlog):
-    def __init__(self, opener, defversion=0):
+    def __init__(self, opener, defversion=REVLOGV0):
         self.mapcache = None
         self.listcache = None
         revlog.__init__(self, opener, "00manifest.i", "00manifest.d",