diff --git a/CMakeLists.txt b/CMakeLists.txt
index cdd38335..f7deab84 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,12 +24,12 @@
 
 cmake_minimum_required(VERSION 3.0)
 # XXX using 1.8.90 instead of 1.9.0-DEV
-project(nghttp2 VERSION 1.50.90)
+project(nghttp2 VERSION 1.51.0)
 
 # See versioning rule:
 #  https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
 set(LT_CURRENT  38)
-set(LT_REVISION 0)
+set(LT_REVISION 1)
 set(LT_AGE      24)
 
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})
diff --git a/configure.ac b/configure.ac
index e43eee93..8b3678b5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,7 +25,7 @@ dnl Do not change user variables!
 dnl https://www.gnu.org/software/automake/manual/html_node/Flag-Variables-Ordering.html
 
 AC_PREREQ(2.61)
-AC_INIT([nghttp2], [1.51.0-DEV], [t-tujikawa@users.sourceforge.net])
+AC_INIT([nghttp2], [1.51.0], [t-tujikawa@users.sourceforge.net])
 AC_CONFIG_AUX_DIR([.])
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_HEADERS([config.h])
@@ -45,7 +45,7 @@ m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 dnl See versioning rule:
 dnl  https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
 AC_SUBST(LT_CURRENT, 38)
-AC_SUBST(LT_REVISION, 0)
+AC_SUBST(LT_REVISION, 1)
 AC_SUBST(LT_AGE, 24)
 
 major=`echo $PACKAGE_VERSION |cut -d. -f1 | sed -e "s/[^0-9]//g"`