diff --git a/configure.ac b/configure.ac
index ab6d5a36..265b86bd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,7 +3,7 @@
 
 AC_PREREQ(2.60)
 AC_INIT([libX11],
-        1.2.2,
+        1.2.99.1,
         [https://bugs.freedesktop.org/enter_bug.cgi?product=xorg],
         libX11)
 AC_CONFIG_SRCDIR([Makefile.am])