diff --git a/CMakeLists.txt b/CMakeLists.txt
index e707229b..c670628d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,7 +11,7 @@ project(mosquitto)
 cmake_minimum_required(VERSION 2.8)
 # Only for version 3 and up. cmake_policy(SET CMP0042 NEW)
 
-set (VERSION 1.6.3)
+set (VERSION 1.6.4)
 
 add_definitions (-DCMAKE -DVERSION=\"${VERSION}\")
 
diff --git a/ChangeLog.txt b/ChangeLog.txt
index 101e3fd7..ba660d80 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -1,4 +1,4 @@
-1.6.4 - 2019xxxx
+1.6.4 - 20190801
 ================
 
 Broker:
diff --git a/config.mk b/config.mk
index e305d0cd..6c23bef9 100644
--- a/config.mk
+++ b/config.mk
@@ -104,7 +104,7 @@ WITH_COVERAGE:=no
 
 # Also bump lib/mosquitto.h, CMakeLists.txt,
 # installer/mosquitto.nsi, installer/mosquitto64.nsi
-VERSION=1.6.3
+VERSION=1.6.4
 
 # Client library SO version. Bump if incompatible API/ABI changes are made.
 SOVERSION=1
diff --git a/installer/mosquitto.nsi b/installer/mosquitto.nsi
index 15cd507d..2190683d 100644
--- a/installer/mosquitto.nsi
+++ b/installer/mosquitto.nsi
@@ -9,7 +9,7 @@
 !define env_hklm 'HKLM "SYSTEM\CurrentControlSet\Control\Session Manager\Environment"'
 
 Name "Eclipse Mosquitto"
-!define VERSION 1.6.3
+!define VERSION 1.6.4
 OutFile "mosquitto-${VERSION}-install-windows-x86.exe"
 
 InstallDir "$PROGRAMFILES\mosquitto"
diff --git a/installer/mosquitto64.nsi b/installer/mosquitto64.nsi
index 6027fc89..12a98b84 100644
--- a/installer/mosquitto64.nsi
+++ b/installer/mosquitto64.nsi
@@ -9,7 +9,7 @@
 !define env_hklm 'HKLM "SYSTEM\CurrentControlSet\Control\Session Manager\Environment"'
 
 Name "Eclipse Mosquitto"
-!define VERSION 1.6.3
+!define VERSION 1.6.4
 OutFile "mosquitto-${VERSION}-install-windows-x64.exe"
 
 !include "x64.nsh"
diff --git a/lib/mosquitto.h b/lib/mosquitto.h
index d939bfd2..6957b619 100644
--- a/lib/mosquitto.h
+++ b/lib/mosquitto.h
@@ -48,7 +48,7 @@ extern "C" {
 
 #define LIBMOSQUITTO_MAJOR 1
 #define LIBMOSQUITTO_MINOR 6
-#define LIBMOSQUITTO_REVISION 3
+#define LIBMOSQUITTO_REVISION 4
 /* LIBMOSQUITTO_VERSION_NUMBER looks like 1002001 for e.g. version 1.2.1. */
 #define LIBMOSQUITTO_VERSION_NUMBER (LIBMOSQUITTO_MAJOR*1000000+LIBMOSQUITTO_MINOR*1000+LIBMOSQUITTO_REVISION)
 
diff --git a/set-version.sh b/set-version.sh
index 0e99da2f..5fe6c80c 100755
--- a/set-version.sh
+++ b/set-version.sh
@@ -2,7 +2,7 @@
 
 MAJOR=1
 MINOR=6
-REVISION=3
+REVISION=4
 
 sed -i "s/^VERSION=.*/VERSION=${MAJOR}.${MINOR}.${REVISION}/" config.mk
 
diff --git a/snap/snapcraft.yaml b/snap/snapcraft.yaml
index cae454fa..95a4eb1f 100644
--- a/snap/snapcraft.yaml
+++ b/snap/snapcraft.yaml
@@ -1,5 +1,5 @@
 name: mosquitto
-version: 1.6.3
+version: 1.6.4
 summary: Eclipse Mosquitto MQTT broker
 description: This is a message broker that supports version 3.1 and 3.1.1 of the MQTT
     protocol.
diff --git a/www/pages/download.md b/www/pages/download.md
index 13aa8ddc..a2acb0e2 100644
--- a/www/pages/download.md
+++ b/www/pages/download.md
@@ -1,7 +1,7 @@
 <!--
 .. title: Download
 .. slug: download
-.. date: 2019-04-30 13:12:00 UTC+1
+.. date: 2019-08-01 13:12:00 UTC+1
 .. tags: tag
 .. category: category
 .. link: link
@@ -11,7 +11,7 @@
 
 # Source
 
-* [mosquitto-1.6.3.tar.gz](https://mosquitto.org/files/source/mosquitto-1.6.3.tar.gz) (319kB) ([GPG signature](https://mosquitto.org/files/source/mosquitto-1.6.3.tar.gz.asc))
+* [mosquitto-1.6.4.tar.gz](https://mosquitto.org/files/source/mosquitto-1.6.4.tar.gz) (319kB) ([GPG signature](https://mosquitto.org/files/source/mosquitto-1.6.4.tar.gz.asc))
 * [Git source code repository](https://github.com/eclipse/mosquitto) (github.com)
 
 Older downloads are available at [https://mosquitto.org/files/](../files/)
@@ -24,8 +24,8 @@ distributions.
 
 ## Windows
 
-* [mosquitto-1.6.3-install-windows-x64.exe](https://mosquitto.org/files/binary/win64/mosquitto-1.6.3-install-windows-x64.exe) (~1.4 MB) (64-bit build, Windows Vista and up, built with Visual Studio Community 2017)
-* [mosquitto-1.6.3-install-windows-x32.exe](https://mosquitto.org/files/binary/win32/mosquitto-1.6.2-install-windows-x86.exe) (~1.4 MB) (32-bit build, Windows Vista and up, built with Visual Studio Community 2017)
+* [mosquitto-1.6.4-install-windows-x64.exe](https://mosquitto.org/files/binary/win64/mosquitto-1.6.4-install-windows-x64.exe) (~1.4 MB) (64-bit build, Windows Vista and up, built with Visual Studio Community 2017)
+* [mosquitto-1.6.4-install-windows-x32.exe](https://mosquitto.org/files/binary/win32/mosquitto-1.6.2-install-windows-x86.exe) (~1.4 MB) (32-bit build, Windows Vista and up, built with Visual Studio Community 2017)
 
 See also readme-windows.txt after installing.
 
diff --git a/www/posts/2019/08/version-1-6-4-released.md b/www/posts/2019/08/version-1-6-4-released.md
new file mode 100644
index 00000000..6b3ca1af
--- /dev/null
+++ b/www/posts/2019/08/version-1-6-4-released.md
@@ -0,0 +1,56 @@
+<!--
+.. title: Version 1.6.4 released
+.. slug: version-1-6-4-released
+.. date: 2019-08-01 18:00:00 UTC+1
+.. tags: Releases
+.. category:
+.. link:
+.. description:
+.. type: text
+-->
+
+This is a bugfix release.
+
+## Broker
+- Fix persistent clients being incorrectly expired on Raspberry Pis.
+  Closes [#1272].
+- Windows: Allow other applications access to the log file when running.
+  Closes [#515].
+- Fix incoming QoS 2 messages being blocked when `max_inflight_messages` was
+  set to 1. Closes [#1332].
+- Fix incoming messages not being removed for a client if the topic being
+  published to does not have any subscribers. Closes [#1322].
+
+## Client library
+- Fix MQTT v5 subscription options being incorrectly set for MQTT v3
+  subscriptions. Closes [#1353].
+- Make behaviour of `mosquitto_connect_async()` consistent with
+  `mosquitto_connect()` when connecting to a non-existent server.
+  Closes [#1345].
+- `mosquitto_string_option(mosq, MOSQ_OPT_TLS_KEYFORM, ...)` was incorrectly
+  returning `MOSQ_ERR_INVAL` with valid input. This has been fixed.
+  Closes [#1360].
+- `on_connect` callback is now called with the correct v5 reason code if a v5
+  client connects to a v3.x broker and is sent a CONNACK with the
+  "unacceptable protocol version" connack reason code.
+- Fix memory leak when setting v5 properties in `mosquitto_connect_v5()`.
+- Fix properties not being sent on QoS>0 PUBLISH messages.
+
+## Clients
+- `mosquitto_pub`: fix error codes not being returned when `mosquitto_pub` exits.
+  Closes [#1354].
+- All clients: improve error messages when connecting to a v3.x broker when in
+  v5 mode. Closes [#1344].
+
+## Other
+- Various documentation fixes.
+
+[#515]: https://github.com/eclipse/mosquitto/issues/515
+[#1272]: https://github.com/eclipse/mosquitto/issues/1272
+[#1322]: https://github.com/eclipse/mosquitto/issues/1322
+[#1332]: https://github.com/eclipse/mosquitto/issues/1332
+[#1344]: https://github.com/eclipse/mosquitto/issues/1344
+[#1345]: https://github.com/eclipse/mosquitto/issues/1345
+[#1353]: https://github.com/eclipse/mosquitto/issues/1353
+[#1354]: https://github.com/eclipse/mosquitto/issues/1354
+[#1360]: https://github.com/eclipse/mosquitto/issues/1360