--- a/python/mozbuild/mozbuild/test/frontend/data/inheriting-variables/foo/baz/moz.build
+++ b/python/mozbuild/mozbuild/test/frontend/data/inheriting-variables/foo/baz/moz.build
@@ -1,7 +1,7 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-XPIDL_MODULE = 'baz'
+DIST_SUBDIR = 'baz'

--- a/python/mozbuild/mozbuild/test/frontend/data/inheriting-variables/moz.build
+++ b/python/mozbuild/mozbuild/test/frontend/data/inheriting-variables/moz.build
@@ -1,10 +1,10 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-XPIDL_MODULE = 'foobar'
-export("XPIDL_MODULE")
+DIST_SUBDIR = 'foobar'
+export('DIST_SUBDIR')
 
 DIRS += ['foo', 'bar']

--- a/python/mozbuild/mozbuild/test/frontend/test_reader.py
+++ b/python/mozbuild/mozbuild/test/frontend/test_reader.py
@@ -260,17 +260,17 @@ class TestBuildReader(unittest.TestCase)
     def test_inheriting_variables(self):
         reader = self.reader('inheriting-variables')
 
         contexts = list(reader.read_topsrcdir())
 
         self.assertEqual(len(contexts), 4)
         self.assertEqual([context.relsrcdir for context in contexts],
             ['', 'foo', 'foo/baz', 'bar'])
-        self.assertEqual([context['XPIDL_MODULE'] for context in contexts],
+        self.assertEqual([context['DIST_SUBDIR'] for context in contexts],
             ['foobar', 'foobar', 'baz', 'foobar'])
 
     def test_find_relevant_mozbuilds(self):
         reader = self.reader('reader-relevant-mozbuild')
 
         # Absolute paths outside topsrcdir are rejected.
         with self.assertRaises(Exception):
             reader._find_relevant_mozbuilds(['/foo'])