diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -54,6 +54,7 @@
     rewriteutil,
     scmutil,
     server,
+    state as statemod,
     streamclone,
     tags as tagsmod,
     templatekw,
@@ -2174,7 +2175,9 @@
             raise error.Abort(_("can't specify --continue and revisions"))
         # read in unfinished revisions
         try:
-            nodes = repo.vfs.read('graftstate').splitlines()
+            with repo.vfs('graftstate', 'rb') as fp:
+                stateopts = statemod.oldgraftstate(fp)
+                nodes = stateopts['nodes']
             revs = [repo[node].rev() for node in nodes]
         except IOError as inst:
             if inst.errno != errno.ENOENT:
diff --git a/mercurial/state.py b/mercurial/state.py
--- a/mercurial/state.py
+++ b/mercurial/state.py
@@ -113,3 +113,8 @@
         oldstatefilefns[path] = func
         return func
     return dec
+
+@readoldstatefile('graftstate')
+def oldgraftstate(fp):
+    nodes = fp.read().splitlines()
+    return {'nodes': nodes}