diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index fb92478ac25..9f41efcb55c 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -197,7 +197,7 @@ builtin_filter(PyObject *self, PyObject *args)
 			break;
 		}
 
-		if (func == Py_None) {
+		if (func == (PyObject *)&PyBool_Type || func == Py_None) {
 			ok = PyObject_IsTrue(item);
 		}
 		else {