diff --git a/configure.ac b/configure.ac
index 9f64bdc6..9acab2c5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,7 +25,7 @@ dnl Do not change user variables!
 dnl http://www.gnu.org/software/automake/manual/html_node/Flag-Variables-Ordering.html
 
 AC_PREREQ(2.61)
-AC_INIT([nghttp2], [1.0.5], [t-tujikawa@users.sourceforge.net])
+AC_INIT([nghttp2], [1.0.6-DEV], [t-tujikawa@users.sourceforge.net])
 AC_USE_SYSTEM_EXTENSIONS
 
 LT_PREREQ([2.2.6])