diff --git a/lib/tls.js b/lib/tls.js
index 2ac43c01d32..5372aadccd6 100644
--- a/lib/tls.js
+++ b/lib/tls.js
@@ -109,8 +109,8 @@ function convertProtocols(protocols) {
     return p + 1 + len;
   }, 0));
 
-  var offset = 0;
-  for (var i = 0, c = protocols.length; i < c; i++) {
+  let offset = 0;
+  for (let i = 0, c = protocols.length; i < c; i++) {
     buff[offset++] = lens[i];
     buff.write(protocols[i], offset);
     offset += lens[i];
@@ -163,7 +163,7 @@ function check(hostParts, pattern, wildcards) {
     return false;
 
   // Check host parts from right to left first.
-  for (var i = hostParts.length - 1; i > 0; i -= 1) {
+  for (let i = hostParts.length - 1; i > 0; i -= 1) {
     if (hostParts[i] !== patternParts[i])
       return false;
   }