diff --git a/Objects/listobject.c b/Objects/listobject.c
index 2edbedf..b53b948 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -1778,7 +1778,7 @@
 	if (!PyArg_UnpackTuple(args, "", 2, 2, &x, &y))
 		return NULL;
 	if (!PyObject_TypeCheck(x, &sortwrapper_type) ||
-	    !PyObject_TypeCheck(x, &sortwrapper_type)) {
+	    !PyObject_TypeCheck(y, &sortwrapper_type)) {
 		PyErr_SetString(PyExc_TypeError, 
 			"expected a sortwrapperobject");
 		return NULL;