diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 444fc1e..cd74758 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2050,7 +2050,7 @@
         /* XXX: The py3k branch gets better errors for this by using
            _PyType_Lookup(), but since float's mro isn't set in py2.6,
            we just use PyObject_CallMethod here. */
-	return PyObject_CallMethod(number, "__trunc__", "");
+	return PyObject_CallMethod(number, "__trunc__", NULL);
 }
 
 PyDoc_STRVAR(trunc_doc,