1 files changed, 15 insertions, 0 deletions
diff --git a/Lib/unittest/test/testmock/testhelpers.py b/Lib/unittest/test/testmock/testhelpers.py
index d2202a7..7919482 100644
--- a/Lib/unittest/test/testmock/testhelpers.py
+++ b/Lib/unittest/test/testmock/testhelpers.py
@@ -1,3 +1,5 @@
+import time
+import types
 import unittest
 
 from unittest.mock import (
@@ -856,6 +858,19 @@ class SpecSignatureTest(unittest.TestCase):
         check_data_descriptor(foo.desc)
 
 
+    def test_autospec_on_bound_builtin_function(self):
+        meth = types.MethodType(time.ctime, time.time())
+        self.assertIsInstance(meth(), str)
+        mocked = create_autospec(meth)
+
+        # no signature, so no spec to check against
+        mocked()
+        mocked.assert_called_once_with()
+        mocked.reset_mock()
+        mocked(4, 5, 6)
+        mocked.assert_called_once_with(4, 5, 6)
+
+
 class TestCallList(unittest.TestCase):
 
     def test_args_list_contains_call_list(self):