diff --git a/ChangeLog b/ChangeLog
index aa8de4e..5ee1648 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Version 4.2.0
+=============
+ * Include wandio version number in the HTTP user-agent
+ * Improved error detection and handling when reading HTTP
+ * Replaced 'off_t' parameters and return values with 'int64_t' in
+   recently added API functions.
+ * Fixed potential uninitialised memory error when closing a wandio writer.
+
 Version 4.1.2
 =============
  * Fix buffer overflow bug in the swift reading code (thanks Alistair).
diff --git a/README b/README
index b778cac..314dc05 100644
--- a/README
+++ b/README
@@ -1,4 +1,4 @@
-WANDIO 4.1.2
+WANDIO 4.2.0
 
 ---------------------------------------------------------------------------
 Copyright (c) 2007-2019 The University of Waikato, Hamilton, New Zealand.
diff --git a/configure.ac b/configure.ac
index ae9d764..691b100 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,11 +3,11 @@
 # Now you only need to update the version number in two places - below,
 # and in the README
 
-AC_INIT([wandio],[4.1.2],[contact@wand.net.nz],[wandio])
+AC_INIT([wandio],[4.2.0],[contact@wand.net.nz],[wandio])
 
 WANDIO_MAJOR=4
-WANDIO_MID=1
-WANDIO_MINOR=2
+WANDIO_MID=2
+WANDIO_MINOR=0
 
 # OpenSolaris hides libraries like libncurses in /usr/gnu/lib, which is not
 # searched by default - add it to LDFLAGS so we at least have a chance of
diff --git a/debian/changelog b/debian/changelog
index 3fba6fb..5d8c657 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,13 @@
+libwandio1 (4.2.0) unstable; urgency=medium
+
+  * Include wandio version number in the HTTP user-agent
+  * Improved error detection and handling when reading HTTP
+  * Replaced 'off_t' parameters and return values with 'int64_t' in
+    recently added API functions.
+  * Fixed potential uninitialised memory error when closing a wandio writer.
+
+ -- Shane Alcock <salcock@waikato.ac.nz>  Fri, 10 May 2019 13:31:49 +1200
+
 libwandio1 (4.1.2-1) unstable; urgency=medium
 
   * Fix swift buffer overflow bug
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 16bb1bc..bd845c5 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -73,5 +73,5 @@ libwandio_la_SOURCES=wandio.c ior-peek.c ior-stdio.c ior-thread.c \
 
 AM_CPPFLAGS = @ADD_INCLS@
 libwandio_la_LIBADD = @LIBWANDIO_LIBS@
-libwandio_la_LDFLAGS=-version-info 5:2:1 @ADD_LDFLAGS@
+libwandio_la_LDFLAGS=-version-info 6:0:0 @ADD_LDFLAGS@
 
diff --git a/rpm/libwandio1.spec b/rpm/libwandio1.spec
index a16bd65..f256b2a 100644
--- a/rpm/libwandio1.spec
+++ b/rpm/libwandio1.spec
@@ -1,6 +1,6 @@
 Name:           libwandio1
-Version:        4.1.2
-Release:        2%{?dist}
+Version:        4.2.0
+Release:        1%{?dist}
 Summary:        C Multi-Threaded File Compression and Decompression Library
 
 License:        LGPLv3
@@ -73,8 +73,8 @@ find $RPM_BUILD_ROOT -name '*.la' -exec rm -f {} ';'
 %{_bindir}/wandiocat
 
 %changelog
-* Thu May 09 2019 Shane Alcock <salcock@waikato.ac.nz> - 4.1.2-2
-- Re-built packages for new repository layout
+* Fri May 10 2019 Shane Alcock <salcock@waikato.ac.nz> - 4.2.0-1
+- New upstream release (4.2.0)
 
 * Thu Feb 21 2019 Shane Alcock <salcock@waikato.ac.nz> - 4.1.0-1
 - First libwandio package