diff --git a/browser/devtools/storage/test/moz.build b/browser/devtools/storage/test/moz.build
deleted file mode 100644
index 33f04f85378..00000000000
--- a/browser/devtools/storage/test/moz.build
+++ /dev/null
@@ -1,8 +0,0 @@
-# -*- 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/.
-
-BROWSER_CHROME_MANIFESTS += ['browser.ini']
-
diff --git a/dom/encoding/test/moz.build b/dom/encoding/test/moz.build
deleted file mode 100644
index 4603ed2376d..00000000000
--- a/dom/encoding/test/moz.build
+++ /dev/null
@@ -1,14 +0,0 @@
-# -*- 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/.
-
-TEST_DIRS += ['unit']
-
-XPCSHELL_TESTS_MANIFESTS += ['unit/xpcshell.ini']
-
-MOCHITEST_MANIFESTS += ['mochitest.ini']
-
-MOCHITEST_CHROME_MANIFESTS += ['chrome.ini']
-
diff --git a/dom/tests/mochitest/fetch/moz.build b/dom/tests/mochitest/fetch/moz.build
deleted file mode 100644
index 8421b15157a..00000000000
--- a/dom/tests/mochitest/fetch/moz.build
+++ /dev/null
@@ -1,7 +0,0 @@
-# -*- 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/.
-
-MOCHITEST_MANIFESTS += ['mochitest.ini']
diff --git a/dom/workers/test/fetch/moz.build b/dom/workers/test/fetch/moz.build
deleted file mode 100644
index 8421b15157a..00000000000
--- a/dom/workers/test/fetch/moz.build
+++ /dev/null
@@ -1,7 +0,0 @@
-# -*- 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/.
-
-MOCHITEST_MANIFESTS += ['mochitest.ini']