diff --git a/hgext/fix.py b/hgext/fix.py
--- a/hgext/fix.py
+++ b/hgext/fix.py
@@ -631,7 +631,7 @@
             proc = subprocess.Popen(
                 procutil.tonativestr(command),
                 shell=True,
-                cwd=repo.root,
+                cwd=procutil.tonativestr(repo.root),
                 stdin=subprocess.PIPE,
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,