diff --git a/Objects/listobject.c b/Objects/listobject.c
index bcc6bc0..51b4e57 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -1944,6 +1944,8 @@ listsort(PyListObject *self, PyObject *args, PyObject *kwds)
             if (keys[i] == NULL) {
                 for (i=i-1 ; i>=0 ; i--)
                     Py_DECREF(keys[i]);
+                if (keys != &ms.temparray[saved_ob_size+1])
+                    PyMem_FREE(keys);
                 goto keyfunc_fail;
             }
         }