diff --git a/.gitignore b/.gitignore
index 7ebea59..38d4126 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,6 @@ SOURCES/nodejs-10.21.0-5.fc32.src.rpm
 SOURCES/nspr-4.25.0-1.el8_0.src.rpm
 SOURCES/nss-3.53.1-3.fc32.src.rpm
 SOURCES/openssl-1.0.2k-19.6.bundle.el7_7.src.rpm
-SOURCES/thunderbird-78.3.1.source.tar.xz
-SOURCES/thunderbird-langpacks-78.3.1-20200929.tar.xz
+SOURCES/thunderbird-78.4.0.source.tar.xz
+SOURCES/thunderbird-langpacks-78.4.0-20201021.tar.xz
 SOURCES/yasm-1.2.0-3.el5.src.rpm
diff --git a/.thunderbird.metadata b/.thunderbird.metadata
index c09d16c..31d5a14 100644
--- a/.thunderbird.metadata
+++ b/.thunderbird.metadata
@@ -6,6 +6,6 @@ e188ab1a444697bc649e223c28389d82ca94c472 SOURCES/libffi-3.0.13-18.el7_3.src.rpm
 07d67c90367c3ec0d6cebc1a5793c21076d34b78 SOURCES/nspr-4.25.0-1.el8_0.src.rpm
 223c02166b1cb9863b9f453ef687d7805a93e7af SOURCES/nss-3.53.1-3.fc32.src.rpm
 a379070abf5000cde61411c97af7e733b267a4d3 SOURCES/openssl-1.0.2k-19.6.bundle.el7_7.src.rpm
-aac14b96dd577ba26504ac0ab5d77fc9a85cede3 SOURCES/thunderbird-78.3.1.source.tar.xz
-286e1da1db164234bf0173ed2a8ee0b5e53a2f11 SOURCES/thunderbird-langpacks-78.3.1-20200929.tar.xz
+66fa85ad999826bb0c53c94497a6879245f879ea SOURCES/thunderbird-78.4.0.source.tar.xz
+a7974489a76c00ff4d9386daff6b1763fc1b40db SOURCES/thunderbird-langpacks-78.4.0-20201021.tar.xz
 77fd30f7ebc12a629a31c1e252cec06af55a71fe SOURCES/yasm-1.2.0-3.el5.src.rpm
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/thunderbird-redhat-default-prefs.js.rhel6 b/SOURCES/thunderbird-redhat-default-prefs.js.rhel6
index c412cb5..26e8d17 100644
--- a/SOURCES/thunderbird-redhat-default-prefs.js.rhel6
+++ b/SOURCES/thunderbird-redhat-default-prefs.js.rhel6
@@ -28,3 +28,6 @@ pref("network.negotiate-auth.allow-insecure-ntlm-v1", true);
 pref("security.use_mozillapkix_verification", false);
 /* Use OS settings for UI language */
 pref("intl.locale.requested", "");
+pref("datareporting.healthreport.uploadEnabled", false);
+pref("datareporting.policy.dataSubmissionEnabled", false);
+pref("toolkit.telemetry.archive.enabled", false);
diff --git a/SOURCES/thunderbird-redhat-default-prefs.js.rhel7 b/SOURCES/thunderbird-redhat-default-prefs.js.rhel7
index c412cb5..26e8d17 100644
--- a/SOURCES/thunderbird-redhat-default-prefs.js.rhel7
+++ b/SOURCES/thunderbird-redhat-default-prefs.js.rhel7
@@ -28,3 +28,6 @@ pref("network.negotiate-auth.allow-insecure-ntlm-v1", true);
 pref("security.use_mozillapkix_verification", false);
 /* Use OS settings for UI language */
 pref("intl.locale.requested", "");
+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 18847dc..0a7e81b 100644
--- a/SPECS/thunderbird.spec
+++ b/SPECS/thunderbird.spec
@@ -191,7 +191,7 @@
 %global build_langpacks         1
 Summary:        Mozilla Thunderbird mail/newsgroup client
 Name:           thunderbird
-Version:        78.3.1
+Version:        78.4.0
 Release:        1%{?dist}
 URL:            http://www.mozilla.org/projects/thunderbird/
 License:        MPLv1.1 or GPLv2+ or LGPLv2+
@@ -207,7 +207,7 @@ ExclusiveArch:  i686 x86_64 ppc64 s390x
 # From ftp://archive.mozilla.org/pub/thunderbird/releases/%{version}%{?ext_version}/source
 Source0:        https://archive.mozilla.org/pub/thunderbird/releases/%{version}%{?pre_version}/source/thunderbird-%{version}%{?pre_version}.source.tar.xz
 %if %{build_langpacks}
-Source1:        thunderbird-langpacks-%{version}%{?ext_version}-20200929.tar.xz
+Source1:        thunderbird-langpacks-%{version}%{?ext_version}-20201021.tar.xz
 # Locales for lightning
 %endif
 Source2:        cbindgen-vendor-0.14.3.tar.xz
@@ -1101,6 +1101,8 @@ CPU_AVAILABLE=$(/usr/bin/getconf _NPROCESSORS_ONLN)
 # gtk3-private-setup-flags-env.inc
 %include_file %{SOURCE205}
 %endif
+
+
 #FIXME workaround for oom
 
 cat /proc/meminfo
@@ -1420,6 +1422,10 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #===============================================================================
 
 %changelog
+* Wed Oct 21 2020 Eike Rathke <erack@redhat.com> - 78.4.0-1
+- Update to 78.4.0 build1
+- Disabled telemetry
+
 * Tue Sep 29 2020 Jan Horak <jhorak@redhat.com> - 78.3.1-1
 - Update to 78.3.1 build1