diff --git a/plugins/op_waf/waf/lua/common.lua b/plugins/op_waf/waf/lua/common.lua
index e1efc1e75..c04ff49f1 100644
--- a/plugins/op_waf/waf/lua/common.lua
+++ b/plugins/op_waf/waf/lua/common.lua
@@ -522,7 +522,7 @@ function _M.get_real_ip(self, server_name)
     self:D("ipheader[0]:"..self:to_json(request_header))
     if self.site_config[server_name] then
         if self.site_config[server_name]['cdn'] then
-            local request_header = self.params["request_header"]
+            local request_header = ngx.req.get_headers()
             for _,v in ipairs(self.site_config[server_name]['cdn_header'])
             do
                 self:D("client_ip[for]:"..tostring(request_header[v]))