diff --git a/lib/internal/readline/utils.js b/lib/internal/readline/utils.js
index 31de512f74ba85..b6957f6e8a1a61 100644
--- a/lib/internal/readline/utils.js
+++ b/lib/internal/readline/utils.js
@@ -16,7 +16,7 @@ let isFullWidthCodePoint;
 
 function CSI(strings, ...args) {
   let ret = `${kEscape}[`;
-  for (var n = 0; n < strings.length; n++) {
+  for (let n = 0; n < strings.length; n++) {
     ret += strings[n];
     if (n < args.length)
       ret += args[n];
@@ -79,7 +79,7 @@ if (internalBinding('config').hasIntl) {
 
     str = stripVTControlCharacters(String(str));
 
-    for (var i = 0; i < str.length; i++) {
+    for (let i = 0; i < str.length; i++) {
       const code = str.codePointAt(i);
 
       if (code >= kUTF16SurrogateThreshold) { // Surrogates.