--- a/im/confvars.sh
+++ b/im/confvars.sh
@@ -1,14 +1,14 @@
 #! /bin/sh
 # 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/.
 
-source ${_topsrcdir}/$MOZ_BUILD_APP/../comm-confvars.sh
+. ${_topsrcdir}/$MOZ_BUILD_APP/../comm-confvars.sh
 
 MOZ_APP_BASENAME=Instantbird
 MOZ_APP_NAME=instantbird
 MOZ_APP_STATIC_INI=1
 MOZ_XUL_APP=1
 MOZ_ENABLE_LIBXUL=1
 MOZ_DISABLE_EXPORT_JS=1
 MOZ_UPDATER=1

--- a/mail/confvars.sh
+++ b/mail/confvars.sh
@@ -1,14 +1,14 @@
 #! /bin/sh
 # 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/.
 
-source ${_topsrcdir}/$MOZ_BUILD_APP/../comm-confvars.sh
+. ${_topsrcdir}/$MOZ_BUILD_APP/../comm-confvars.sh
 
 MOZ_APP_BASENAME=Thunderbird
 MOZ_APP_NAME=thunderbird
 MOZ_UPDATER=1
 MOZ_THUNDERBIRD=1
 MOZ_LDAP_XPCOM=1
 MOZ_COMPOSER=1
 MOZ_ALLOW_LEGACY_EXTENSIONS=1

--- a/suite/confvars.sh
+++ b/suite/confvars.sh
@@ -1,14 +1,14 @@
 #! /bin/sh
 # 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/.
 
-source ${_topsrcdir}/$MOZ_BUILD_APP/../comm-confvars.sh
+. ${_topsrcdir}/$MOZ_BUILD_APP/../comm-confvars.sh
 
 MOZ_APP_BASENAME=SeaMonkey
 MOZ_APP_VENDOR=Mozilla
 MOZ_APP_NAME=seamonkey
 MOZ_APP_DISPLAYNAME=SeaMonkey
 MOZ_LDAP_XPCOM=1
 MOZ_COMPOSER=1
 MOZ_SUITE=1