diff --git a/dune.module b/dune.module
index bffa16cb6075f21bd15b724826779edb1938ad30..93e9bc950e322773e23769e509a949f537b6d251 100644
--- a/dune.module
+++ b/dune.module
@@ -1,4 +1,4 @@
 Module: dune-istl
-Version: 2.3-svn
+Version: 2.3-mn
 Maintainer: dune-devel@dune-project.org
 Depends: dune-common (>= 2.3)
diff --git a/m4/dune_istl.m4 b/m4/dune_istl.m4
index 1c03bc230d2c1091aa56330201320e228fec0ac8..c334b822775371988e9452bb3b25ae3b7e8e9600 100644
--- a/m4/dune_istl.m4
+++ b/m4/dune_istl.m4
@@ -1,5 +1,7 @@
 AC_DEFUN([DUNE_ISTL_CHECKS],
 [
+  AC_DEFINE(DUNE_ISTL_FLAVOR_MN, 1, [This is Martin's personal development version of dune-istl!])
+
   AC_REQUIRE([DUNE_PATH_PARMETIS])
   AC_REQUIRE([DUNE_PATH_SUPERLU])
   AC_REQUIRE([DUNE_PATH_SUPERLU_DIST])