diff --git a/.gitignore b/.gitignore
index 84b22a9..4b673a1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,3 @@
-SOURCES/l10n-lightning-38.2.0.tar.bz2
-SOURCES/thunderbird-38.2.0.source.tar.bz2
-SOURCES/thunderbird-langpacks-38.2.0-20150814.tar.bz2
+SOURCES/l10n-lightning-38.3.0.tar.bz2
+SOURCES/thunderbird-38.3.0.source.tar.bz2
+SOURCES/thunderbird-langpacks-38.3.0-20150929.tar.bz2
diff --git a/.thunderbird.metadata b/.thunderbird.metadata
index 8dc6416..9a90ff6 100644
--- a/.thunderbird.metadata
+++ b/.thunderbird.metadata
@@ -1,3 +1,3 @@
-372a8235cb2a99ab2d2d9cc67ed7912c4c2f23e0 SOURCES/l10n-lightning-38.2.0.tar.bz2
-0e27c54ee63b71cd7e8ff4fd87bbe66e0a16ffc1 SOURCES/thunderbird-38.2.0.source.tar.bz2
-5c5969a2692bf970db3062b128691e4fa2fb3676 SOURCES/thunderbird-langpacks-38.2.0-20150814.tar.bz2
+b944cb59b3fcc16198a0647bc5c289d9a77c0411 SOURCES/l10n-lightning-38.3.0.tar.bz2
+7c8ef066d6b6516fddbb654b38353f894f85d469 SOURCES/thunderbird-38.3.0.source.tar.bz2
+8b452489a8cb44b72c37321ef3921f63c900c178 SOURCES/thunderbird-langpacks-38.3.0-20150929.tar.bz2
diff --git a/SOURCES/thunderbird-centos-default-prefs.js b/SOURCES/thunderbird-centos-default-prefs.js
deleted file mode 100644
index 013aa21..0000000
--- a/SOURCES/thunderbird-centos-default-prefs.js
+++ /dev/null
@@ -1,28 +0,0 @@
-pref("app.update.enabled", false);
-pref("app.update.autoInstallEnabled", false);
-# Allow users to set custom colors
-# pref("browser.display.use_system_colors",   true);
-pref("general.useragent.vendor", "CentOS");
-pref("general.useragent.vendorSub", "THUNDERBIRD_RPM_VR");
-pref("intl.locale.matchOS", true);
-pref("mail.shell.checkDefaultClient", false);
-pref("toolkit.networkmanager.disable", false);
-pref("offline.autoDetect", true);
-
-# Disable global indexing by default
-pref("mailnews.database.global.indexer.enabled", false);
-
-# Do not switch to Smart Folders after upgrade to 3.0b4
-pref("mail.folder.views.version", "1")
-pref("extensions.shownSelectionUI", true);
-pref("extensions.autoDisableScope", 0);
-
-# For rhbz#1024232
-pref("ui.SpellCheckerUnderlineStyle",       1);
-
-/* Workaround for rhbz#1134876 */
-pref("javascript.options.baselinejit",      false);
-/* Workaround for rhbz#1110291 */
-pref("network.negotiate-auth.allow-insecure-ntlm-v1", true);
-/* Workaround for mozbz#1063315 */
-pref("security.use_mozillapkix_verification", false);
diff --git a/SOURCES/thunderbird-redhat-default-prefs.js b/SOURCES/thunderbird-redhat-default-prefs.js
new file mode 100644
index 0000000..af23193
--- /dev/null
+++ b/SOURCES/thunderbird-redhat-default-prefs.js
@@ -0,0 +1,28 @@
+pref("app.update.enabled", false);
+pref("app.update.autoInstallEnabled", false);
+# Allow users to set custom colors
+# pref("browser.display.use_system_colors",   true);
+pref("general.useragent.vendor", "Red Hat");
+pref("general.useragent.vendorSub", "THUNDERBIRD_RPM_VR");
+pref("intl.locale.matchOS", true);
+pref("mail.shell.checkDefaultClient", false);
+pref("toolkit.networkmanager.disable", false);
+pref("offline.autoDetect", true);
+
+# Disable global indexing by default
+pref("mailnews.database.global.indexer.enabled", false);
+
+# Do not switch to Smart Folders after upgrade to 3.0b4
+pref("mail.folder.views.version", "1")
+pref("extensions.shownSelectionUI", true);
+pref("extensions.autoDisableScope", 0);
+
+# For rhbz#1024232
+pref("ui.SpellCheckerUnderlineStyle",       1);
+
+/* Workaround for rhbz#1134876 */
+pref("javascript.options.baselinejit",      false);
+/* Workaround for rhbz#1110291 */
+pref("network.negotiate-auth.allow-insecure-ntlm-v1", true);
+/* Workaround for mozbz#1063315 */
+pref("security.use_mozillapkix_verification", false);
diff --git a/SPECS/thunderbird.spec b/SPECS/thunderbird.spec
index 47a96b6..d7da7a1 100644
--- a/SPECS/thunderbird.spec
+++ b/SPECS/thunderbird.spec
@@ -64,14 +64,14 @@
 
 Summary:        Mozilla Thunderbird mail/newsgroup client
 Name:           thunderbird
-Version:        38.2.0
+Version:        38.3.0
 Release:        1%{?dist}
 URL:            http://www.mozilla.org/projects/thunderbird/
 License:        MPLv1.1 or GPLv2+ or LGPLv2+
 Group:          Applications/Internet
 Source0:        ftp://ftp.mozilla.org/pub/thunderbird/releases/%{version}%{?pre_version}/source/thunderbird-%{version}%{?pre_version}.source.tar.bz2
 %if %{build_langpacks}
-Source1:        thunderbird-langpacks-%{version}-20150814.tar.bz2
+Source1:        thunderbird-langpacks-%{version}-20150929.tar.bz2
 %endif
 # Locales for lightning
 Source2:        l10n-lightning-%{version}.tar.bz2
@@ -79,7 +79,7 @@ Source3:        mklangsource.sh
 
 Source10:       thunderbird-mozconfig
 Source11:       thunderbird-mozconfig-branded
-Source12:       thunderbird-centos-default-prefs.js
+Source12:       thunderbird-redhat-default-prefs.js
 Source20:       thunderbird.desktop
 Source21:       thunderbird.sh.in
 Source100:      find-external-requires
@@ -161,6 +161,7 @@ BuildRequires:  libicu-devel
 Requires:       mozilla-filesystem
 BuildRequires:  libffi-devel
 Obsoletes:      thunderbird-lightning
+Obsoletes:      thunderbird-lightning-gdata
 
 %define _use_internal_dependency_generator 0
 %define __find_requires %{SOURCE100}
@@ -586,8 +587,8 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #===============================================================================
 
 %changelog
-* Tue Aug 25 2015 CentOS Sources <bugs@centos.org> - 38.2.0-1.el7.centos
-- rebrand default prefs
+* Tue Sep 29 2015 Jan Horak <jhorak@redhat.com> - 38.3.0-1
+- Update to 38.3.0
 
 * Fri Aug 14 2015 Jan Horak <jhorak@redhat.com> - 38.2.0-1
 - Update to 38.2.0