diff --git a/hgext/hgk.py b/hgext/hgk.py
index 3da626e..61239e8 100644
--- a/hgext/hgk.py
+++ b/hgext/hgk.py
@@ -335,7 +335,7 @@ def revtree(ui, args, repo, full="tree", maxnr=0, parents=False):
     ('[OPTION]... REV...'))
 def revlist(ui, repo, *revs, **opts):
     """print revisions"""
-    if opts['header']:
+    if opts[u'header']:
         full = "commit"
     else:
         full = None