diff --git a/confs/site/main-lua.conf b/confs/site/main-lua.conf
index 4ef8a5d..213d026 100644
--- a/confs/site/main-lua.conf
+++ b/confs/site/main-lua.conf
@@ -96,21 +96,17 @@ end
 
 -- check if user-agent is allowed
 if use_user_agent and ngx.var.bad_user_agent == "yes" then
-	local headers = ngx.req.get_headers()
-	local ua = headers["User-Agent"]
-	if not whitelist_user_agent ~= "" then
-		local k_ua_white, v_ua_white = next(whitelist_user_agent, nil)
-		while v_ua_white do
-			local rst_whitelist = string.match(ua, v_ua_white)
-			if rst_whitelist ~= nil and rst_whitelist ~= "" then
-				ngx.log(ngx.WARN, "[ALLOW] User-Agent " .. ngx.var.http_user_agent .. " is whitelisted")
-				ngx.exit(ngx.OK)
-			end
-			k_ua_white, v_ua_white = next(whitelist_user_agent, k_ua_white)
-		end
+	for k, v in pairs(whitelist_user_agent) then
+		if string.match(ngx.var.http_user_agent, v) then
+			ngx.log(ngx.WARN, "[ALLOW] User-Agent " .. ngx.var.http_user_agent .. " is whitelisted")
+			block = false
+			break
+		fi
+	end
+	if block then
+		ngx.log(ngx.WARN, "[BLOCK] User-Agent " .. ngx.var.http_user_agent .. " is blacklisted")
+		ngx.exit(ngx.HTTP_FORBIDDEN)
 	end
-	ngx.log(ngx.WARN, "[BLOCK] User-Agent " .. ngx.var.http_user_agent .. " is blacklisted")
-	ngx.exit(ngx.HTTP_FORBIDDEN)
 end
 
 -- check if referrer is allowed