1 files changed, 1 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index 65304f58..dc893b74 100644
--- a/configure.ac
+++ b/configure.ac
@@ -144,6 +144,7 @@ X11_EXT_XKB
 X11_EXT_XRANDR
 X11_EXT_SHAPE
 X11_EXT_XINERAMA
+X11_EXT_SYNC
 
 AC_CONFIG_FILES([
   Makefile