Index: configure.ac
===================================================================
--- configure.ac	(revision 5483)
+++ configure.ac	(working copy)
@@ -1455,7 +1455,9 @@
 ])
 
 BRLTTY_HAVE_PACKAGE([dbus], ["dbus-1 >= 1.0"], [dnl
-   BRLTTY_SCREEN_DRIVER([a2], [AtSpi2], [$(DBUS_LIBS)])
+   AC_CHECK_HEADERS([X11/keysym.h], [dnl
+      BRLTTY_SCREEN_DRIVER([a2], [AtSpi2], [$(DBUS_LIBS)])
+   ])
 ])
 
 BRLTTY_ARG_DRIVER([screen], [Screen])