diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -21,7 +21,7 @@
 
 from mercurial.i18n import _
 from mercurial.node import (
-    nullid,
+    nullhex,
     nullrev,
     short,
 )
@@ -252,7 +252,7 @@
                     else:
                         destrev = legacydest
                     destmap[oldrev] = destrev
-                    if newrev in (nullid, revtodostr):
+                    if newrev in (nullhex, revtodostr):
                         state[oldrev] = revtodo
                         # Legacy compat special case
                     else: