diff -r 6147a2c99db0 Lib/test/test_with.py
--- a/Lib/test/test_with.py	Mon May 23 08:42:09 2016 +0300
+++ b/Lib/test/test_with.py	Mon May 23 20:16:41 2016 -0700
@@ -109,7 +109,7 @@
             with foo: pass
         self.assertRaises(NameError, fooNotDeclared)
 
-    def testEnterAttributeError(self):
+    def testEnterAttributeError1(self):
         class LacksEnter(object):
             def __exit__(self, type, value, traceback):
                 pass
@@ -117,7 +117,16 @@
         def fooLacksEnter():
             foo = LacksEnter()
             with foo: pass
-        self.assertRaises(AttributeError, fooLacksEnter)
+        self.assertRaisesRegexp(AttributeError, '__enter__', fooLacksEnter)
+
+    def testEnterAttributeError2(self):
+        class LacksEnterAndExit(object):
+            pass
+
+        def fooLacksEnterAndExit():
+            foo = LacksEnterAndExit()
+            with foo: pass
+        self.assertRaisesRegexp(AttributeError, '__enter__', fooLacksEnterAndExit)
 
     def testExitAttributeError(self):
         class LacksExit(object):
@@ -127,7 +136,7 @@
         def fooLacksExit():
             foo = LacksExit()
             with foo: pass
-        self.assertRaises(AttributeError, fooLacksExit)
+        self.assertRaisesRegexp(AttributeError, '__exit__', fooLacksExit)
 
     def assertRaisesSyntaxError(self, codestr):
         def shouldRaiseSyntaxError(s):
diff -r 6147a2c99db0 Python/ceval.c
--- a/Python/ceval.c	Mon May 23 08:42:09 2016 +0300
+++ b/Python/ceval.c	Mon May 23 20:16:41 2016 -0700
@@ -3066,15 +3066,15 @@
             _Py_IDENTIFIER(__exit__);
             _Py_IDENTIFIER(__enter__);
             PyObject *mgr = TOP();
-            PyObject *exit = special_lookup(mgr, &PyId___exit__), *enter;
+            PyObject *enter = special_lookup(mgr, &PyId___enter__), *exit;
             PyObject *res;
+            if (enter == NULL)
+                goto error;
+            exit = special_lookup(mgr, &PyId___exit__);
             if (exit == NULL)
                 goto error;
             SET_TOP(exit);
-            enter = special_lookup(mgr, &PyId___enter__);
             Py_DECREF(mgr);
-            if (enter == NULL)
-                goto error;
             res = PyObject_CallFunctionObjArgs(enter, NULL);
             Py_DECREF(enter);
             if (res == NULL)