diff --git a/extensions/python/xpcom/src/PyIVariant.cpp b/extensions/python/xpcom/src/PyIVariant.cpp
index 8d1f0dcd4dd..ca5524408af 100644
--- a/extensions/python/xpcom/src/PyIVariant.cpp
+++ b/extensions/python/xpcom/src/PyIVariant.cpp
@@ -141,12 +141,11 @@ static PyObject *GetAsInterface(PyObject *self, PyObject *args) {
 static PyObject *GetAsISupports(PyObject *self, PyObject *args) {
 	nsIVariant *pI = GetI(self);
 	if (pI==NULL) return NULL;
-	if (!PyArg_ParseTuple(args, ":GetAsInterface")) return NULL;
+	if (!PyArg_ParseTuple(args, ":GetAsISupports")) return NULL;
 	nsCOMPtr<nsISupports> p;
-	nsIID *iid;
-	nsresult nr = pI->GetAsInterface(&iid, getter_AddRefs(p));
+	nsresult nr = pI->GetAsISupports(getter_AddRefs(p));
 	if (NS_FAILED(nr)) return PyXPCOM_BuildPyException(nr);
-	return Py_nsISupports::PyObjectFromInterface(p, *iid);
+	return Py_nsISupports::PyObjectFromInterface(p, NS_GET_IID(nsISupports));
 }
 
 extern PyObject *PyObject_FromVariantArray( Py_nsISupports*, nsIVariant *v);