diff --git a/hgext/githelp.py b/hgext/githelp.py
--- a/hgext/githelp.py
+++ b/hgext/githelp.py
@@ -115,7 +115,7 @@
     args = list([convert(x) for x in args])
     opts = dict(
         [
-            (k, convert(v)) if isinstance(v, str) else (k, v)
+            (k, convert(v)) if isinstance(v, bytes) else (k, v)
             for k, v in pycompat.iteritems(opts)
         ]
     )