diff --git a/NEWS b/NEWS
index 329cc51ad..68457a365 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,7 @@
+New in spot 2.12.1.dev  (not yet released)
+
+  Nothing yet.
+
 New in spot 2.12.1  (2024-09-23)
 
   Bug fixes:
diff --git a/configure.ac b/configure.ac
index 9f229582b..6f64eab68 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 AC_PREREQ([2.69])
-AC_INIT([spot], [2.12.1], [spot@lrde.epita.fr])
+AC_INIT([spot], [2.12.1.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])