diff -r 6c2e2de5ab8e Objects/listobject.c
--- a/Objects/listobject.c	Sat Jul 30 23:51:13 2016 -0700
+++ b/Objects/listobject.c	Wed Aug 03 00:22:35 2016 +0800
@@ -47,23 +47,17 @@
      * The growth pattern is:  0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ...
      */
     new_allocated = (newsize >> 3) + (newsize < 9 ? 3 : 6);
-
-    /* check for integer overflow */
-    if (new_allocated > PY_SIZE_MAX - newsize) {
+    /* can't overflow, largest number is PY_SSIZE_T_MAX * (9 / 8) + 6 */
+    new_allocated += (size_t)newsize;
+    if (new_allocated > (size_t)PY_SSIZE_T_MAX) {
         PyErr_NoMemory();
         return -1;
-    } else {
-        new_allocated += newsize;
     }
 
     if (newsize == 0)
         new_allocated = 0;
     items = self->ob_item;
-    if (new_allocated <= (PY_SIZE_MAX / sizeof(PyObject *)))
-        PyMem_RESIZE(items, PyObject *, new_allocated);
-    else
-        items = NULL;
-    if (items == NULL) {
+    if (!PyMem_RESIZE(items, PyObject *, new_allocated)) {
         PyErr_NoMemory();
         return -1;
     }