--- a/toolkit/components/maintenanceservice/moz.build
+++ b/toolkit/components/maintenanceservice/moz.build
@@ -8,24 +8,19 @@ Program('maintenanceservice')
 
 SOURCES += [
     'maintenanceservice.cpp',
     'servicebase.cpp',
     'serviceinstall.cpp',
     'workmonitor.cpp',
 ]
 
-if CONFIG['OS_ARCH'] == 'WINNT':
-    USE_LIBS += [
-        'updatecommon-standalone',
-    ]
-else:
-    USE_LIBS += [
-        'updatecommon',
-    ]
+USE_LIBS += [
+    'updatecommon',
+]
 
 # For debugging purposes only
 #DEFINES['DISABLE_UPDATER_AUTHENTICODE_CHECK'] = True
 
 DEFINES['UNICODE'] = True
 DEFINES['_UNICODE'] = True
 DEFINES['NS_NO_XPCOM'] = True
 

--- a/toolkit/moz.build
+++ b/toolkit/moz.build
@@ -18,22 +18,19 @@ DIRS += [
     'pluginproblem',
     'profile',
     'themes',
 ]
 
 if CONFIG['MOZ_UPDATER'] and CONFIG['MOZ_WIDGET_TOOLKIT'] != 'android':
     DIRS += ['mozapps/update']
 
-if CONFIG['MOZ_MAINTENANCE_SERVICE'] or CONFIG['MOZ_UPDATER'] and CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
-# Including mozapps/update/common-standalone allows the maintenance service
-# to be built so the maintenance service can be used for things other than
-# updating applications.
+if CONFIG['MOZ_MAINTENANCE_SERVICE'] or CONFIG['MOZ_UPDATER']:
     DIRS += [
-        'mozapps/update/common-standalone',
+        'mozapps/update/common',
     ]
 
 if CONFIG['MOZ_MAINTENANCE_SERVICE']:
     DIRS += [
         'components/maintenanceservice'
     ]
 
 DIRS += ['xre']

deleted file mode 100644
--- a/toolkit/mozapps/update/common-standalone/moz.build
+++ /dev/null
@@ -1,12 +0,0 @@
-# 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/.
-
-Library('updatecommon-standalone')
-
-srcdir = '../common'
-
-include('../common/sources.mozbuild')
-
-if CONFIG['OS_ARCH'] == 'WINNT':
-    USE_STATIC_LIBS = True

--- a/toolkit/mozapps/update/common/moz.build
+++ b/toolkit/mozapps/update/common/moz.build
@@ -21,12 +21,30 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'wind
         EXPORTS += [
             'certificatecheck.h',
             'registrycertificates.h',
         ]
 
 Library('updatecommon')
 
 DEFINES['NS_NO_XPCOM'] = True
+USE_STATIC_LIBS = True
 
-srcdir = '.'
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
+    SOURCES += [
+        'pathhash.cpp',
+        'uachelper.cpp',
+        'updatehelper.cpp',
+    ]
+    if CONFIG['MOZ_MAINTENANCE_SERVICE']:
+        SOURCES += [
+            'certificatecheck.cpp',
+            'registrycertificates.cpp',
+        ]
+        OS_LIBS += [
+            'crypt32',
+            'wintrust',
+        ]
 
-include('sources.mozbuild')
+SOURCES += [
+    'readstrings.cpp',
+    'updatecommon.cpp',
+]

deleted file mode 100644
--- a/toolkit/mozapps/update/common/sources.mozbuild
+++ /dev/null
@@ -1,28 +0,0 @@
-# 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/.
-
-sources = []
-
-if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
-    sources += [
-        'pathhash.cpp',
-        'uachelper.cpp',
-        'updatehelper.cpp',
-    ]
-    if CONFIG['MOZ_MAINTENANCE_SERVICE']:
-        sources += [
-            'certificatecheck.cpp',
-            'registrycertificates.cpp',
-        ]
-        OS_LIBS += [
-            'crypt32',
-            'wintrust',
-        ]
-
-sources += [
-    'readstrings.cpp',
-    'updatecommon.cpp',
-]
-
-SOURCES += sorted(['%s/%s' % (srcdir, s) for s in sources])

--- a/toolkit/mozapps/update/moz.build
+++ b/toolkit/mozapps/update/moz.build
@@ -2,17 +2,16 @@
 # 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 = 'update'
 
 DIRS += [
-    'common',
     'updater',
 ]
 
 XPIDL_SOURCES += [
     'nsIUpdateService.idl',
 ]
 
 TEST_DIRS += ['tests']

--- a/toolkit/mozapps/update/tests/moz.build
+++ b/toolkit/mozapps/update/tests/moz.build
@@ -27,27 +27,23 @@ SimplePrograms([
 ])
 
 LOCAL_INCLUDES += [
     '/toolkit/mozapps/update',
     '/toolkit/mozapps/update/common',
 ]
 
 if CONFIG['OS_ARCH'] == 'WINNT':
-    USE_LIBS += [
-        'updatecommon-standalone',
-    ]
-
     OS_LIBS += [
         'shlwapi',
       ]
-else:
-    USE_LIBS += [
-        'updatecommon',
-    ]
+
+USE_LIBS += [
+    'updatecommon',
+]
 
 for var in ('MOZ_APP_NAME', 'MOZ_APP_BASENAME', 'MOZ_APP_DISPLAYNAME',
             'MOZ_APP_VENDOR', 'BIN_SUFFIX', 'MOZ_DEBUG'):
     DEFINES[var] = CONFIG[var]
 
 DEFINES['NS_NO_XPCOM'] = True
 
 if CONFIG['MOZ_MAINTENANCE_SERVICE']:

--- a/toolkit/mozapps/update/updater/updater-common.build
+++ b/toolkit/mozapps/update/updater/updater-common.build
@@ -28,41 +28,34 @@ if CONFIG['OS_ARCH'] == 'WINNT':
     DEFINES['UNICODE'] = True
     DEFINES['_UNICODE'] = True
     USE_STATIC_LIBS = True
 
     # Pick up nsWindowsRestart.cpp
     LOCAL_INCLUDES += [
         '/toolkit/xre',
     ]
-    USE_LIBS += [
-        'updatecommon-standalone',
-    ]
     OS_LIBS += [
         'comctl32',
         'ws2_32',
         'shell32',
         'shlwapi',
         'crypt32',
         'advapi32',
     ]
 elif CONFIG['OS_ARCH'] == 'Linux' and CONFIG['MOZ_VERIFY_MAR_SIGNATURE']:
     USE_LIBS += [
         'nss',
         'signmar',
-        'updatecommon',
     ]
     OS_LIBS += CONFIG['NSPR_LIBS']
-else:
-    USE_LIBS += [
-        'updatecommon',
-    ]
 
 USE_LIBS += [
     'mar',
+    'updatecommon',
     'xz-embedded',
 ]
 
 if CONFIG['MOZ_SYSTEM_BZ2']:
     OS_LIBS += CONFIG['MOZ_BZ2_LIBS']
 else:
     USE_LIBS += [
         'bz2',