Add sentinel
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 046548d..5f1b167 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -2919,6 +2919,7 @@
 static PyMethodDef count_methods[] = {
 	{"__reduce__",	(PyCFunction)count_reduce,	METH_NOARGS,
 	 count_reduce_doc},
+	{NULL,		NULL}	/* sentinel */
 };
 
 PyDoc_STRVAR(count_doc,