--- a/mercurial/hg.py	Thu Jun 22 03:16:16 2017 +0530
+++ b/mercurial/hg.py	Thu Jun 22 03:20:11 2017 +0530
@@ -130,7 +130,7 @@
 
 def islocal(repo):
     '''return true if repo (or path pointing to repo) is local'''
-    if isinstance(repo, str):
+    if isinstance(repo, bytes):
         try:
             return _peerlookup(repo).islocal(repo)
         except AttributeError: