diff -r 10b965d59b49 Objects/odictobject.c
--- a/Objects/odictobject.c	Thu Oct 22 20:19:14 2015 +0300
+++ b/Objects/odictobject.c	Thu Oct 22 22:13:48 2015 +0300
@@ -481,10 +481,12 @@ struct _odictobject {
     PyDictObject od_dict;        /* the underlying dict */
     _ODictNode *od_first;        /* first node in the linked list, if any */
     _ODictNode *od_last;         /* last node in the linked list, if any */
-    /* od_fast_nodes and od_resize_sentinel are managed by _odict_resize()
+    /* od_fast_nodes, od_resize_sentinel and od_resize_sentinel2 are managed
+     * by _odict_resize().
      * Note that we rely on implementation details of dict for both. */
     _ODictNode **od_fast_nodes;  /* hash table that mirrors the dict table */
-    Py_uintptr_t od_resize_sentinel;  /* changes if odict should be resized */
+    void *od_resize_sentinel;  /* changes if odict should be resized */
+    Py_ssize_t od_resize_sentinel2;  /* changes if odict should be resized */
 
     size_t od_state;             /* incremented whenever the LL changes */
     PyObject *od_inst_dict;      /* OrderedDict().__dict__ */
@@ -573,7 +575,8 @@ static int
     /* Replace the old fast nodes table. */
     _odict_free_fast_nodes(od);
     od->od_fast_nodes = fast_nodes;
-    od->od_resize_sentinel = (Py_uintptr_t)(((PyDictObject *)od)->ma_keys);
+    od->od_resize_sentinel = ((PyDictObject *)od)->ma_keys;
+    od->od_resize_sentinel2 = ((PyDictObject *)od)->ma_keys->dk_size;
     return 0;
 }
 
@@ -591,7 +594,8 @@ static Py_ssize_t
     keys = ((PyDictObject *)od)->ma_keys;
 
     /* Ensure od_fast_nodes and dk_entries are in sync. */
-    if (od->od_resize_sentinel != (Py_uintptr_t)keys) {
+    if (od->od_resize_sentinel != keys ||
+        od->od_resize_sentinel2 != keys->dk_size) {
         int resize_res = _odict_resize(od);
         if (resize_res < 0)
             return -1;