diff --git a/CHANGES b/CHANGES
index f4ff86d2..e38b859b 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,5 +1,8 @@
 CHANGES FROM 2.9 to 3.0
 
+* Workaround invalid layout strings generated by older tmux versions and add
+  some additional sanity checks
+
 * xterm 348 now disables margins when resized, so send DECLRMM again after
   resize.
 
diff --git a/configure.ac b/configure.ac
index 8b7f171e..57c3fd73 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,6 +1,6 @@
 # configure.ac
 
-AC_INIT([tmux], 3.0)
+AC_INIT([tmux], 3.0a)
 AC_PREREQ([2.60])
 
 AC_CONFIG_AUX_DIR(etc)