--- a/mercurial/help.py	Wed May 03 15:25:06 2017 +0530
+++ b/mercurial/help.py	Fri Apr 28 00:49:30 2017 +0530
@@ -23,6 +23,7 @@
     filemerge,
     fileset,
     minirst,
+    pycompat,
     revset,
     templatefilters,
     templatekw,
@@ -304,6 +305,7 @@
     '''
 
     from . import commands # avoid cycle
+    opts = pycompat.byteskwargs(opts)
 
     def helpcmd(name, subtopic=None):
         try: