Index: trunk/Modules/cPickle.c
===================================================================
--- trunk/Modules/cPickle.c     (revision 64448)
+++ trunk/Modules/cPickle.c     (working copy)
@@ -1519,6 +1519,7 @@
        PyObject *obj;
        PyObject *slice[BATCHSIZE];
        int i, n;
+       self->nesting++;
 
        static char append = APPEND;
        static char appends = APPENDS;
@@ -1658,6 +1659,7 @@
        PyObject *p;
        PyObject *slice[BATCHSIZE];
        int i, n;
+       self->nesting++;
 
        static char setitem = SETITEM;
        static char setitems = SETITEMS;