+local default_log = require "util.logger".init("xmppstream");
+
+-- COMPAT: w/LuaExpat 1.1.0
+local lxp_supports_doctype = pcall(lxp.new, { StartDoctypeDecl = false });
+
+if not lxp_supports_doctype then
+ default_log("warn", "The version of LuaExpat on your system leaves Prosody "
+ .."vulnerable to denial-of-service attacks. You should upgrade to "
+ .."LuaExpat 1.1.1 or higher as soon as possible. See "
+ .."http://prosody.im/doc/depends#luaexpat for more information.");
+end