diff --git a/NEWS b/NEWS
index 6ac9e6198..11a6c17ed 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,7 @@
+New in spot 2.6.1.dev (not yet released)
+
+  Nothing yet.
+
 New in spot 2.6.1  (2018-08-04)
 
   Command-line tools:
diff --git a/configure.ac b/configure.ac
index 7af2fa897..5d69ccc8e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -21,7 +21,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 AC_PREREQ([2.61])
-AC_INIT([spot], [2.6.1], [spot@lrde.epita.fr])
+AC_INIT([spot], [2.6.1.dev], [spot@lrde.epita.fr])
 AC_CONFIG_AUX_DIR([tools])
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([1.11 gnu tar-ustar color-tests parallel-tests])