diff --git a/configure.ac b/configure.ac
index 16a3b7051565555d6cf4eab1ca5603e2c4e0ecc4..112aeb0f2fb9b8d1d95499e41c054f5053d80b1f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7,7 +7,7 @@
 AC_PREREQ([2.69])
 LT_PREREQ([2.4.6])
 
-AC_INIT([cdi],[2.5.1],[https://mpimet.mpg.de/cdi])
+AC_INIT([cdi],[2.5.1.1],[https://mpimet.mpg.de/cdi])
 AC_DEFINE_UNQUOTED(CDI, ["$PACKAGE_VERSION"], [CDI version])
 
 AC_CONFIG_AUX_DIR([config])