diff -r a6bc96c2b8be Modules/_pickle.c
--- a/Modules/_pickle.c	Tue Nov 17 00:19:27 2015 +0000
+++ b/Modules/_pickle.c	Tue Nov 17 11:21:44 2015 +0100
@@ -193,6 +193,7 @@ static void
     Py_CLEAR(st->import_mapping_3to2);
     Py_CLEAR(st->codecs_encode);
     Py_CLEAR(st->getattr);
+    Py_CLEAR(st->partial);
 }
 
 /* Initialize the given pickle module state. */