diff --git a/rootfs/etc/nginx/lua/test/util/resolv_conf_test.lua b/rootfs/etc/nginx/lua/test/util/resolv_conf_test.lua
index b8c706d1b2..b700d4754d 100644
--- a/rootfs/etc/nginx/lua/test/util/resolv_conf_test.lua
+++ b/rootfs/etc/nginx/lua/test/util/resolv_conf_test.lua
@@ -30,6 +30,7 @@ describe("resolv_conf", function()
 # This is a comment
 nameserver 10.96.0.10
 nameserver 10.96.0.99
+nameserver 2001:4860:4860::8888
 search ingress-nginx.svc.cluster.local svc.cluster.local cluster.local
 options ndots:5
     ]===]
@@ -37,7 +38,7 @@ options ndots:5
     helpers.with_resolv_conf(conf, function()
       local resolv_conf = require("util.resolv_conf")
       assert.are.same({
-        nameservers = { "10.96.0.10", "10.96.0.99" },
+        nameservers = { "10.96.0.10", "10.96.0.99", "[2001:4860:4860::8888]" },
         search = { "ingress-nginx.svc.cluster.local", "svc.cluster.local", "cluster.local" },
         ndots = 5,
       }, resolv_conf)
diff --git a/rootfs/etc/nginx/lua/util/resolv_conf.lua b/rootfs/etc/nginx/lua/util/resolv_conf.lua
index 9dd015d435..82cd1d83bb 100644
--- a/rootfs/etc/nginx/lua/util/resolv_conf.lua
+++ b/rootfs/etc/nginx/lua/util/resolv_conf.lua
@@ -1,4 +1,5 @@
 local ngx_re_split = require("ngx.re").split
+local string_format = string.format
 
 local ngx_log = ngx.log
 local ngx_ERR = ngx.ERR
@@ -52,7 +53,7 @@ local function parse_line(line)
 
   if keyword == "nameserver" then
     if not value:match("^%d+.%d+.%d+.%d+$") then
-      value = string.format("[%s]", value)
+      value = string_format("[%s]", value)
     end
     nameservers[#nameservers + 1] = value
   elseif keyword == "search" then