diff --git a/pytest_mock.py b/pytest_mock.py
index b893acc..f4c1c25 100644
--- a/pytest_mock.py
+++ b/pytest_mock.py
@@ -1,6 +1,7 @@
 from pprint import pformat
 import inspect
 
+import py
 import pytest
 
 try:
@@ -8,6 +9,8 @@
 except ImportError:
     import unittest.mock as mock_module
 
+u = py.builtin._totext
+
 version = '1.2'
 
 
@@ -152,12 +155,12 @@ def mock(mocker):
 _mock_module_originals = {}
 
 
-DETAILED_ASSERTION = """{original!s}
+DETAILED_ASSERTION = u("""{original!s}
 
 ... pytest introspection follows:
 {detailed!s}
-"""
-FULL_ANY_CALLS_DIFF = "{call} in {calls_list}"
+""")
+FULL_ANY_CALLS_DIFF = u("{call} in {calls_list}")
 
 
 def pytest_assertrepr_compare(config, op, left, right):
@@ -187,12 +190,12 @@ def safe_unpack_args(call):
         try:
             assert largs == rargs
         except AssertionError as e:
-            msg.extend(['args introspection:', str(e)])
+            msg.extend(['args introspection:', u(e)])
 
         try:
             assert lkwargs == rkwargs
         except AssertionError as e:
-            msg.extend(['kwargs introspection:', str(e)])
+            msg.extend(['kwargs introspection:', u(e)])
         return msg
 
     if (isinstance(left, tuple) and
@@ -216,8 +219,8 @@ def assert_wrapper(__wrapped_mock_method__, *args, **kwargs):
                     assert assert_call == __mock_self.call_args
             except AssertionError as diff:
                 # raise a new detailed exception, appending to existing
-                msg = DETAILED_ASSERTION.format(original=e, detailed=diff)
-                err = AssertionError(msg.encode().decode('unicode_escape'))
+                msg = DETAILED_ASSERTION.format(original=u(e), detailed=u(diff))
+                err = AssertionError(msg.replace('\\n', '\n').encode('unicode_escape').decode('unicode_escape'))
                 err._msg_updated = True
                 raise err
         raise AssertionError(*e.args)
diff --git a/test_pytest_mock.py b/test_pytest_mock.py
index 925f2c3..6e373a0 100644
--- a/test_pytest_mock.py
+++ b/test_pytest_mock.py
@@ -1,12 +1,15 @@
+# coding=utf-8
 import os
 import platform
 import sys
 from contextlib import contextmanager
 
+import py
 import py.code
 
 import pytest
 
+u = py.builtin._totext
 pytest_plugins = 'pytester'
 
 # could not make some of the tests work on PyPy, patches are welcome!
@@ -561,3 +564,38 @@ def test_assertion_error_is_descriptive(mocker):
 
     assert mocker_any_call.startswith(mock_error_message)
     assert "assert call(1, 2) in [call(" in mocker_any_call
+
+
+def test_assertion_wrap_unicode(mocker):
+    """Verify assert_wrapper properly handles unicode call parts"""
+    mocker_mock = mocker.patch('os.remove')
+    mocker_mock(u('א', 'utf-8'), b=u('ב', 'utf-8'))
+
+    # arguments assertion for last call
+    try:
+        mocker_mock.assert_called_with(u('ג', 'utf-8'), b=u('ד', 'utf-8'))
+    except AssertionError as e:
+        called_with_msg = e.msg
+
+    verbose = any(a.startswith('-v') for a in sys.argv)
+    if verbose:
+        assert u("('ג',) == ('א',)", 'utf-8') in called_with_msg
+        assert u("assert {'b': 'ד'} == {'b': 'ב'}", 'utf-8') in called_with_msg
+        assert u("Use -v to get the full diff", 'utf-8') not in called_with_msg
+    else:
+        assert (
+            (u("Expected call: remove(u'\\u05d2', b=u'\\u05d3')", 'utf-8') in called_with_msg) or
+            (u("Expected call: remove('\u05d2', b='\u05d3')", 'utf-8') in called_with_msg)
+        )
+        assert u("assert {'b': 'ד'} == {'b': 'ב'}", 'utf-8') in called_with_msg
+        assert u('Use -v to get the full diff', 'utf-8') in called_with_msg
+
+    try:
+        mocker_mock.assert_any_call(1, 2)
+    except AssertionError as e:
+        any_call_msg = e.msg
+
+    assert (
+        u("assert call(1, 2) in [call(u'\\u05d0'", 'utf-8') in any_call_msg or
+        u("assert call(1, 2) in [call('\u05d0'", 'utf-8') in any_call_msg
+    )