diff --git a/.gitignore b/.gitignore
index 7a95a98..ebf05a4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,7 @@
 SOURCES/Python-2.7.8.tgz
 SOURCES/devtoolset-2-binutils-2.23.52.0.1-10.el5.src.rpm
 SOURCES/gcc48-4.8.2-16.el5.src.rpm
-SOURCES/l10n-lightning-52.3.0.tar.xz
-SOURCES/thunderbird-52.3.0.source.tar.xz
-SOURCES/thunderbird-langpacks-52.3.0-20170821.tar.xz
+SOURCES/l10n-lightning-52.4.0.tar.xz
+SOURCES/thunderbird-52.4.0.source.tar.xz
+SOURCES/thunderbird-langpacks-52.4.0-20171004.tar.xz
 SOURCES/yasm-1.2.0-3.el5.src.rpm
diff --git a/.thunderbird.metadata b/.thunderbird.metadata
index 944fc9a..7ea53d7 100644
--- a/.thunderbird.metadata
+++ b/.thunderbird.metadata
@@ -1,7 +1,7 @@
 511960dd78451a06c9df76509635aeec05b2051a SOURCES/Python-2.7.8.tgz
 467bdb846d67c01aed9e521fe0ef280065a50c3c SOURCES/devtoolset-2-binutils-2.23.52.0.1-10.el5.src.rpm
 e5ba84786af5d0e0e23b1a9112c76821ef23306c SOURCES/gcc48-4.8.2-16.el5.src.rpm
-2de6d69509152779515510f25818401e6c255912 SOURCES/l10n-lightning-52.3.0.tar.xz
-5dc18774e599af3d50a9ff66d28e861a41e4bb5a SOURCES/thunderbird-52.3.0.source.tar.xz
-4b9bd7337cb3fdb28ad20562514f0400fa655626 SOURCES/thunderbird-langpacks-52.3.0-20170821.tar.xz
+8378918770817c45b8920830110f61b5d7698501 SOURCES/l10n-lightning-52.4.0.tar.xz
+f20e774313df3cac0b6f14586e3d3ca0195d7b90 SOURCES/thunderbird-52.4.0.source.tar.xz
+5ae1833e79c11ab9a4fc57f83947dc9de31f83b8 SOURCES/thunderbird-langpacks-52.4.0-20171004.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/build-nss-version.patch b/SOURCES/build-nss-version.patch
index 30b670b..42f375d 100644
--- a/SOURCES/build-nss-version.patch
+++ b/SOURCES/build-nss-version.patch
@@ -5,7 +5,7 @@ diff -up firefox-52.0esr/old-configure.in.nss-ver firefox-52.0esr/old-configure.
      _USE_SYSTEM_NSS=1 )
  
  if test -n "$_USE_SYSTEM_NSS"; then
--    AM_PATH_NSS(3.28.5, [MOZ_SYSTEM_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])
+-    AM_PATH_NSS(3.28.6, [MOZ_SYSTEM_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])
 +    AM_PATH_NSS(3.28.4, [MOZ_SYSTEM_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])
  fi
  
diff --git a/SPECS/thunderbird.spec b/SPECS/thunderbird.spec
index 0c18e84..2a56f53 100644
--- a/SPECS/thunderbird.spec
+++ b/SPECS/thunderbird.spec
@@ -74,19 +74,19 @@
 
 Summary:        Mozilla Thunderbird mail/newsgroup client
 Name:           thunderbird
-Version:        52.3.0
-Release:        1%{?dist}
+Version:        52.4.0
+Release:        2%{?dist}
 URL:            http://www.mozilla.org/projects/thunderbird/
 License:        MPLv1.1 or GPLv2+ or LGPLv2+
 Group:          Applications/Internet
 
-%define         tarballdir              thunderbird-52.3.0
+%define         tarballdir              thunderbird-52.4.0
 %define         objdir                  objdir
 
 # 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}-20170821.tar.xz
+Source1:        thunderbird-langpacks-%{version}%{?ext_version}-20171004.tar.xz
 %endif
 # Locales for lightning
 Source2:        l10n-lightning-%{version}.tar.xz
@@ -858,6 +858,9 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #===============================================================================
 
 %changelog
+* Wed Oct  4 2017 Jan Horak <jhorak@redhat.com> - 52.4.0-2
+- Update to 52.4.0 (b2)
+
 * Mon Aug 21 2017 Jan Horak <jhorak@redhat.com> - 52.3.0-1
 - Update to 52.3.0