handle dict subclasses gracefully in PyArg_ValidateKeywordArguments
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 1015772..df8d77f 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -454,7 +454,7 @@
 {
     Py_ssize_t pos = 0;
     PyObject *key, *value;
-    assert(PyDict_CheckExact(dict));
+    assert(PyDict_Check(dict));
     /* Shortcut */
     if (((PyDictObject *)dict)->ma_lookup == lookdict_unicode)
         return 1;