diff --git a/dom/canvas/moz.build b/dom/canvas/moz.build
index eafa9144150..310ea9f11f6 100644
--- a/dom/canvas/moz.build
+++ b/dom/canvas/moz.build
@@ -4,9 +4,16 @@
 # 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 += ['test']
 TEST_DIRS += ['compiledtest']
 
+MOCHITEST_MANIFESTS += [
+    'test/crossorigin/mochitest.ini',
+    'test/mochitest-subsuite-webgl.ini',
+    'test/mochitest.ini',
+]
+
+MOCHITEST_CHROME_MANIFESTS += ['test/chrome/chrome.ini']
+
 EXPORTS += [
     'nsICanvasRenderingContextInternal.h',
 ]
diff --git a/dom/canvas/test/moz.build b/dom/canvas/test/moz.build
deleted file mode 100644
index 8cdcfad35b2..00000000000
--- a/dom/canvas/test/moz.build
+++ /dev/null
@@ -1,13 +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 += [
-    'crossorigin/mochitest.ini',
-    'mochitest-subsuite-webgl.ini',
-    'mochitest.ini',
-]
-
-MOCHITEST_CHROME_MANIFESTS += ['chrome/chrome.ini']
diff --git a/dom/smil/moz.build b/dom/smil/moz.build
index f25e7df798b..5f999ae7e49 100644
--- a/dom/smil/moz.build
+++ b/dom/smil/moz.build
@@ -4,7 +4,7 @@
 # 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 += ['test']
+MOCHITEST_MANIFESTS += ['test/mochitest.ini']
 
 EXPORTS += [
     'nsISMILAttr.h',
diff --git a/dom/smil/test/moz.build b/dom/smil/test/moz.build
deleted file mode 100644
index 3cf16eb0cfe..00000000000
--- a/dom/smil/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/.
-
-MOCHITEST_MANIFESTS += ['mochitest.ini']
-
diff --git a/dom/xml/moz.build b/dom/xml/moz.build
index 3f6de0c8610..9fbf5f7c784 100644
--- a/dom/xml/moz.build
+++ b/dom/xml/moz.build
@@ -6,7 +6,7 @@
 
 DIRS += ['resources']
 
-TEST_DIRS += ['test']
+MOCHITEST_MANIFESTS += ['test/mochitest.ini']
 
 EXPORTS += [
     'nsIXMLContentSink.h',
diff --git a/dom/xml/test/moz.build b/dom/xml/test/moz.build
deleted file mode 100644
index 3cf16eb0cfe..00000000000
--- a/dom/xml/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/.
-
-MOCHITEST_MANIFESTS += ['mochitest.ini']
-