diff --git a/cf/check-xau.m4 b/cf/check-xau.m4
new file mode 100644
index 000000000..ce512d65a
--- /dev/null
+++ b/cf/check-xau.m4
@@ -0,0 +1,24 @@
+dnl $Id$
+dnl
+dnl check for Xau{Read,Write}Auth
+dnl
+AC_DEFUN(AC_CHECK_XAU,[
+save_CFLAGS="$CFLAGS"
+CFLAGS="$X_CFLAGS $CFLAGS"
+save_LIBS="$LIBS"
+dnl LIBS="$X_LIBS $X_PRE_LIBS $X_EXTRA_LIBS $LIBS"
+LIBS="$X_PRE_LIBS $X_EXTRA_LIBS $LIBS"
+save_LDFLAGS="$LDFLAGS"
+LDFLAGS="$LDFLAGS $X_LIBS"
+
+AC_FIND_FUNC_NO_LIBS(XauReadAuth, Xau X11)
+ac_xxx="$LIBS"
+LIBS="$LIB_XauReadAuth $LIBS"
+AC_CHECK_FUNCS(XauWriteAuth)
+LIBS="$ac_xxx"
+AM_CONDITIONAL(NEED_WRITEAUTH, test "$ac_cv_func_XauWriteAuth" != "yes")
+
+CFLAGS=$save_CFLAGS
+LIBS=$save_LIBS
+LDFLAGS=$save_LDFLAGS
+])