diff --git a/Objects/cellobject.c b/Objects/cellobject.c
index 490afe0..50a3897 100644
--- a/Objects/cellobject.c
+++ b/Objects/cellobject.c
@@ -51,6 +51,18 @@
 	PyObject_GC_Del(op);
 }
 
+static int
+cell_compare(PyCellObject *a, PyCellObject *b)
+{
+	if (a->ob_ref == NULL) {
+		if (b->ob_ref == NULL)
+			return 0;
+		return -1;
+	} else if (b->ob_ref == NULL)
+		return 1;
+	return PyObject_Compare(a->ob_ref, b->ob_ref);
+}
+
 static PyObject *
 cell_repr(PyCellObject *op)
 {
@@ -102,7 +114,7 @@
 	0,                                      /* tp_print */
 	0,	                                /* tp_getattr */
 	0,					/* tp_setattr */
-	0,					/* tp_compare */
+	(cmpfunc)cell_compare,					/* tp_compare */
 	(reprfunc)cell_repr,			/* tp_repr */
 	0,					/* tp_as_number */
 	0,			                /* tp_as_sequence */