diff --git a/plugins/op_waf/waf/lua/init.lua b/plugins/op_waf/waf/lua/init.lua
index 53f91f674..0073d2aa2 100644
--- a/plugins/op_waf/waf/lua/init.lua
+++ b/plugins/op_waf/waf/lua/init.lua
@@ -531,6 +531,7 @@ end
 
 
 function waf()
+    if server_name =="unset" then ngx.exit(403) end
     min_route()
     -- C:D("min_route")