--- contrib/python/pytest-mock/py2/pytest_mock/plugin.py	(index)
+++ contrib/python/pytest-mock/py2/pytest_mock/plugin.py	(working tree)
@@ -5,6 +5,7 @@ import inspect
 import sys
 
 import pytest
+import six
 
 from ._version import version
 
@@ -172,7 +173,7 @@ class MockFixture(object):
             if info.code_context is None:
                 # no source code available (#169)
                 return
-            code_context = " ".join(info.code_context).strip()
+            code_context = " ".join(six.ensure_text(x) for x in info.code_context).strip()
 
             if code_context.startswith("with mocker."):
                 raise ValueError(