diff --git a/mitogen/parent.py b/mitogen/parent.py
index 92be06ef..7b79155e 100644
--- a/mitogen/parent.py
+++ b/mitogen/parent.py
@@ -76,8 +76,10 @@ itervalues = getattr(dict, 'itervalues', dict.values)
 if mitogen.core.PY3:
     xrange = range
     closure_attr = '__closure__'
+    IM_SELF_ATTR = '__self__'
 else:
     closure_attr = 'func_closure'
+    IM_SELF_ATTR = 'im_self'
 
 
 try:
@@ -786,8 +788,9 @@ class CallSpec(object):
     def _get_name(self):
         bits = [self.func.__module__]
         if inspect.ismethod(self.func):
-            bits.append(getattr(self.func.__self__, '__name__', None) or
-                        getattr(type(self.func.__self__), '__name__', None))
+            im_self = getattr(self.func, IM_SELF_ATTR)
+            bits.append(getattr(im_self, '__name__', None) or
+                        getattr(type(im_self), '__name__', None))
         bits.append(self.func.__name__)
         return u'.'.join(bits)
 
@@ -1472,9 +1475,10 @@ class CallChain(object):
             raise TypeError(self.lambda_msg)
 
         if inspect.ismethod(fn):
-            if not inspect.isclass(fn.__self__):
+            im_self = getattr(fn, IM_SELF_ATTR)
+            if not inspect.isclass(im_self):
                 raise TypeError(self.method_msg)
-            klass = mitogen.core.to_text(fn.__self__.__name__)
+            klass = mitogen.core.to_text(im_self.__name__)
         else:
             klass = None
 
diff --git a/tests/call_function_test.py b/tests/call_function_test.py
index 06d74a8e..9e821b27 100644
--- a/tests/call_function_test.py
+++ b/tests/call_function_test.py
@@ -6,6 +6,7 @@ import unittest2
 import mitogen.core
 import mitogen.parent
 import mitogen.master
+from mitogen.core import str_partition
 
 import testlib
 import plain_old_module
@@ -50,7 +51,7 @@ class CallFunctionTest(testlib.RouterMixin, testlib.TestCase):
 
     def setUp(self):
         super(CallFunctionTest, self).setUp()
-        self.local = self.router.fork()
+        self.local = self.router.local()
 
     def test_succeeds(self):
         self.assertEqual(3, self.local.call(function_that_adds_numbers, 1, 2))
@@ -65,11 +66,11 @@ class CallFunctionTest(testlib.RouterMixin, testlib.TestCase):
         exc = self.assertRaises(mitogen.core.CallError,
             lambda: self.local.call(function_that_fails))
 
-        s = str(exc)
-        etype, _, s = s.partition(': ')
-        self.assertEqual(etype, 'plain_old_module.MyError')
+        s = mitogen.core.to_text(exc)
+        etype, _, s = str_partition(s, u': ')
+        self.assertEqual(etype, u'plain_old_module.MyError')
 
-        msg, _, s = s.partition('\n')
+        msg, _, s = str_partition(s, u'\n')
         self.assertEqual(msg, 'exception text')
 
         # Traceback
@@ -127,7 +128,7 @@ class CallChainTest(testlib.RouterMixin, testlib.TestCase):
 
     def setUp(self):
         super(CallChainTest, self).setUp()
-        self.local = self.router.fork()
+        self.local = self.router.local()
 
     def test_subsequent_calls_produce_same_error(self):
         chain = self.klass(self.local, pipelined=True)
@@ -162,7 +163,7 @@ class UnsupportedCallablesTest(testlib.RouterMixin, testlib.TestCase):
 
     def setUp(self):
         super(UnsupportedCallablesTest, self).setUp()
-        self.local = self.router.fork()
+        self.local = self.router.local()
 
     def test_closures_unsuppored(self):
         a = 1