diff --git a/.gitignore b/.gitignore
index 115ad83..114f12d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,5 @@
 SOURCES/cbindgen-vendor.tar.xz
 SOURCES/nspr-4.32.0-1.el8_1.src.rpm
-SOURCES/nss-3.67.0-6.el8_1.src.rpm
-SOURCES/thunderbird-91.3.0.processed-source.tar.xz
-SOURCES/thunderbird-langpacks-91.3.0-20211102.tar.xz
+SOURCES/nss-3.67.0-7.el8_1.src.rpm
+SOURCES/thunderbird-91.4.0.processed-source.tar.xz
+SOURCES/thunderbird-langpacks-91.4.0-20211206.tar.xz
diff --git a/.thunderbird.metadata b/.thunderbird.metadata
index c13e973..4f4bb2b 100644
--- a/.thunderbird.metadata
+++ b/.thunderbird.metadata
@@ -1,5 +1,5 @@
 c822547dbc12e2baebdfdfb38b665e23f0c2513a SOURCES/cbindgen-vendor.tar.xz
 b5fd1332d8e0d37339ae170c7bebcb63a40b22e0 SOURCES/nspr-4.32.0-1.el8_1.src.rpm
-29da2158892dc108a7a21fd8411fccf0061481b3 SOURCES/nss-3.67.0-6.el8_1.src.rpm
-b46bdec3cb1e38095ad6862e2368e1ae21047fee SOURCES/thunderbird-91.3.0.processed-source.tar.xz
-13db069583d772237cfe01779476867d11ba2ed6 SOURCES/thunderbird-langpacks-91.3.0-20211102.tar.xz
+8fff814901e03c2518ede2f8992d898f5ba61ed9 SOURCES/nss-3.67.0-7.el8_1.src.rpm
+b547aff4246db7d2c7c6e9ff0f0be49ead13bfdb SOURCES/thunderbird-91.4.0.processed-source.tar.xz
+3d730091ab572437549ce4271b407c39b3289045 SOURCES/thunderbird-langpacks-91.4.0-20211206.tar.xz
diff --git a/README.debrand b/README.debrand
deleted file mode 100644
index 01c46d2..0000000
--- a/README.debrand
+++ /dev/null
@@ -1,2 +0,0 @@
-Warning: This package was configured for automatic debranding, but the changes
-failed to apply.
diff --git a/SOURCES/Bug-1238661---fix-mozillaSignalTrampoline-to-work-.patch b/SOURCES/Bug-1238661---fix-mozillaSignalTrampoline-to-work-.patch
deleted file mode 100644
index 6dfe2ad..0000000
--- a/SOURCES/Bug-1238661---fix-mozillaSignalTrampoline-to-work-.patch
+++ /dev/null
@@ -1,12 +0,0 @@
-diff -up firefox-60.0/mfbt/LinuxSignal.h.mozilla-1238661 firefox-60.0/mfbt/LinuxSignal.h
---- firefox-60.0/mfbt/LinuxSignal.h.mozilla-1238661	2018-04-27 08:55:38.848241768 +0200
-+++ firefox-60.0/mfbt/LinuxSignal.h	2018-04-27 09:06:47.946769859 +0200
-@@ -22,7 +22,7 @@ __attribute__((naked)) void SignalTrampo
-                                              void* aContext) {
-   asm volatile("nop; nop; nop; nop" : : : "memory");
- 
--  asm volatile("b %0" : : "X"(H) : "memory");
-+  asm volatile("bx %0" : : "r"(H), "l"(aSignal), "l"(aInfo), "l"(aContext) : "memory");
- }
- 
- #  define MOZ_SIGNAL_TRAMPOLINE(h) (mozilla::SignalTrampoline<h>)
diff --git a/SOURCES/Bug-1526653---fix_user_vfp_armv7.patch b/SOURCES/Bug-1526653---fix_user_vfp_armv7.patch
deleted file mode 100644
index 3f84f95..0000000
--- a/SOURCES/Bug-1526653---fix_user_vfp_armv7.patch
+++ /dev/null
@@ -1,35 +0,0 @@
-From fd6847c9416f9eebde636e21d794d25d1be8791d Mon Sep 17 00:00:00 2001
-From: Mike Hommey <mh@glandium.org>
-Date: Sat, 1 Jun 2019 09:06:01 +0900
-Subject: [PATCH] Bug 1526653 - Include struct definitions for user_vfp and
- user_vfp_exc.
-
----
- js/src/wasm/WasmSignalHandlers.cpp | 11 ++++++++++-
- 1 file changed, 10 insertions(+), 1 deletion(-)
-
-diff --git a/js/src/wasm/WasmSignalHandlers.cpp b/js/src/wasm/WasmSignalHandlers.cpp
-index 636537f8478..383c380f04c 100644
---- a/js/src/wasm/WasmSignalHandlers.cpp
-+++ b/js/src/wasm/WasmSignalHandlers.cpp
-@@ -248,7 +248,16 @@ using mozilla::DebugOnly;
- #endif
- 
- #ifdef WASM_EMULATE_ARM_UNALIGNED_FP_ACCESS
--#  include <sys/user.h>
-+struct user_vfp {
-+  unsigned long long fpregs[32];
-+  unsigned long fpscr;
-+};
-+
-+struct user_vfp_exc {
-+  unsigned long fpexc;
-+  unsigned long fpinst;
-+  unsigned long fpinst2;
-+};
- #endif
- 
- #if defined(ANDROID)
--- 
-2.20.1
-
diff --git a/SOURCES/thunderbird-centos-default-prefs.js.el7 b/SOURCES/thunderbird-centos-default-prefs.js.el7
deleted file mode 100644
index c27d9d3..0000000
--- a/SOURCES/thunderbird-centos-default-prefs.js.el7
+++ /dev/null
@@ -1,36 +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.autoDisableScopes", 0);
-
-/* For rhbz#1024232 */
-pref("ui.SpellCheckerUnderlineStyle",       1);
-
-/* Workaround for rhbz#1753011 */
-pref("spellchecker.dictionary_path", "/usr/share/myspell");
-/* 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);
-/* Use OS settings for UI language */
-pref("intl.locale.requested", "");
-/* Disable telemetry */
-pref("datareporting.healthreport.uploadEnabled", false);
-pref("datareporting.policy.dataSubmissionEnabled", false);
-pref("toolkit.telemetry.archive.enabled", false);
diff --git a/SPECS/thunderbird.spec b/SPECS/thunderbird.spec
index 5a9ff9b..64f3df5 100644
--- a/SPECS/thunderbird.spec
+++ b/SPECS/thunderbird.spec
@@ -128,7 +128,7 @@ end}
 %global build_langpacks         1
 Summary:        Mozilla Thunderbird mail/newsgroup client
 Name:           thunderbird
-Version:        91.3.0
+Version:        91.4.0
 Release:        2%{?dist}
 URL:            http://www.mozilla.org/projects/thunderbird/
 License:        MPLv1.1 or GPLv2+ or LGPLv2+
@@ -151,7 +151,7 @@ ExcludeArch:    s390 ppc
 # Link to official tarball: https://archive.mozilla.org/pub/thunderbird/releases/%%{version}%%{?pre_version}/source/thunderbird-%%{version}%%{?pre_version}.source.tar.xz
 Source0:        thunderbird-%{version}%{?pre_version}.processed-source.tar.xz
 %if %{build_langpacks}
-Source1:        thunderbird-langpacks-%{version}%{?ext_version}-20211102.tar.xz
+Source1:        thunderbird-langpacks-%{version}%{?ext_version}-20211206.tar.xz
 %endif
 Source2:        cbindgen-vendor.tar.xz
 Source3:        get-calendar-langpacks.sh
@@ -163,9 +163,9 @@ Source21:       thunderbird.sh.in
 Source24:       mozilla-api-key
 Source27:       google-api-key
 Source28:       node-stdout-nonblocking-wrapper
-Source701:      thunderbird-centos-default-prefs.js.el7
+Source701:      thunderbird-redhat-default-prefs.js.rhel7
 
-Source403:      nss-3.67.0-6.el8_1.src.rpm
+Source403:      nss-3.67.0-7.el8_1.src.rpm
 Source401:      nss-setup-flags-env.inc
 Source402:      nspr-4.32.0-1.el8_1.src.rpm
 
@@ -1151,11 +1151,14 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #===============================================================================
 
 %changelog
-* Thu Nov 04 2021 CentOS Sources <bugs@centos.org> - 91.3.0-2.el8.centos
-- Apply debranding changes
+* Mon Dec 06 2021 Eike Rathke <erack@redhat.com> - 91.4.0-2
+- Update to 91.4.0 build2
+
+* Wed Dec 01 2021 Eike Rathke <erack@redhat.com> - 91.4.0-1
+- Update to 91.4.0 build1
 
 * Tue Nov 02 2021 Eike Rathke <erack@redhat.com> - 91.3.0-2
-- Update to 19.3.0 build2
+- Update to 91.3.0 build2
 
 * Mon Nov 01 2021 Eike Rathke <erack@redhat.com> - 91.3.0-1
 - Update to 91.3.0 build1