diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index b85bfb2..8f9e813 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2256,16 +2256,12 @@
         return NULL;
     if (v == NULL) {
         d = PyEval_GetLocals();
-        if (d == NULL)
-            return NULL;
-        Py_INCREF(d);
+        Py_XINCREF(d);
     }
     else {
-        d = _PyObject_GetAttrId(v, &PyId___dict__);
-        if (d == NULL) {
+        if (_PyObject_LookupAttrId(v, &PyId___dict__, &d) == 0) {
             PyErr_SetString(PyExc_TypeError,
                 "vars() argument must have __dict__ attribute");
-            return NULL;
         }
     }
     return d;