diff --git a/lib/internal/dns/utils.js b/lib/internal/dns/utils.js
index 70097663546a1a..226d134680a661 100644
--- a/lib/internal/dns/utils.js
+++ b/lib/internal/dns/utils.js
@@ -52,7 +52,7 @@ class Resolver {
       if (typeof serv !== 'string') {
         throw new ERR_INVALID_ARG_TYPE(`servers[${index}]`, 'string', serv);
       }
-      var ipVersion = isIP(serv);
+      let ipVersion = isIP(serv);
 
       if (ipVersion !== 0)
         return newSet.push([ipVersion, serv, IANA_DNS_PORT]);