diff -r 5b33829badcc Objects/setobject.c
--- a/Objects/setobject.c	Mon Oct 24 23:49:51 2016 +0300
+++ b/Objects/setobject.c	Sun Oct 30 17:55:41 2016 -0500
@@ -26,6 +26,7 @@
 
 #include "Python.h"
 #include "structmember.h"
+#include "pyhash.h"
 
 /* Object used as dummy key to fill deleted entries */
 static PyObject _dummy_struct;
@@ -789,8 +790,10 @@
     /* Factor in the number of active entries */
     hash ^= ((Py_uhash_t)PySet_GET_SIZE(self) + 1) * 1927868237UL;
 
-    /* Disperse patterns arising in nested frozensets */
-    hash = hash * 69069U + 907133923UL;
+    /* Disperse patterns arising in nested frozensets and combinations
+       of entries with unlucky hashes */
+    PyHash_FuncDef * hash_func = PyHash_GetFuncDef();
+    hash = (Py_uhash_t)(*hash_func).hash(&hash, sizeof(Py_uhash_t));
 
     /* -1 is reserved as an error code */
     if (hash == (Py_uhash_t)-1)