diff --git a/configure.ac b/configure.ac
index 0f2b046f27cd0bf5c33df9fb48a83ce15bbbf67c..7c764eb6ed3cde5d02d7d584770690ad74a2bbd1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,7 +3,7 @@ dnl Process this file with autoconf to produce a configure script.
 dnl graph-tool package version number
 m4_define(graph_tool_version_major, 2)
 m4_define(graph_tool_version_minor, 2)
-m4_define(graph_tool_version_micro, 14)
+m4_define(graph_tool_version_micro, 15dev)
 
 AC_INIT([graph-tool],[graph_tool_version_major().graph_tool_version_minor().graph_tool_version_micro()],[http://graph-tool.skewed.de])