diff --git a/lib/internal/util.js b/lib/internal/util.js
index f4c08ecdddbdaf..787e07014cfad8 100644
--- a/lib/internal/util.js
+++ b/lib/internal/util.js
@@ -385,21 +385,6 @@ function promisify(original) {
 
 promisify.custom = kCustomPromisifiedSymbol;
 
-// The built-in Array#join is slower in v8 6.0
-function join(output, separator) {
-  let str = '';
-  if (output.length !== 0) {
-    const lastIndex = output.length - 1;
-    for (let i = 0; i < lastIndex; i++) {
-      // It is faster not to use a template string here
-      str += output[i];
-      str += separator;
-    }
-    str += output[lastIndex];
-  }
-  return str;
-}
-
 // As of V8 6.6, depending on the size of the array, this is anywhere
 // between 1.5-10x faster than the two-arg version of Array#splice()
 function spliceOne(list, index) {
@@ -579,7 +564,6 @@ module.exports = {
   getSystemErrorName,
   isError,
   isInsideNodeModules,
-  join,
   lazyDOMException,
   lazyDOMExceptionClass,
   normalizeEncoding,
diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js
index abbb0d9c8ebc86..f53e1797057d7b 100644
--- a/lib/internal/util/inspect.js
+++ b/lib/internal/util/inspect.js
@@ -114,7 +114,6 @@ const {
 const {
   customInspectSymbol,
   isError,
-  join,
   removeColors
 } = require('internal/util');
 
@@ -2057,7 +2056,7 @@ function reduceToSingleString(
         const start = output.length + ctx.indentationLvl +
                       braces[0].length + base.length + 10;
         if (isBelowBreakLength(ctx, output, start, base)) {
-          const joinedOutput = join(output, ', ');
+          const joinedOutput = ArrayPrototypeJoin(output, ', ');
           if (!StringPrototypeIncludes(joinedOutput, '\n')) {
             return `${base ? `${base} ` : ''}${braces[0]} ${joinedOutput}` +
               ` ${braces[1]}`;
@@ -2068,12 +2067,12 @@ function reduceToSingleString(
     // Line up each entry on an individual line.
     const indentation = `\n${StringPrototypeRepeat(' ', ctx.indentationLvl)}`;
     return `${base ? `${base} ` : ''}${braces[0]}${indentation}  ` +
-      `${join(output, `,${indentation}  `)}${indentation}${braces[1]}`;
+      `${ArrayPrototypeJoin(output, `,${indentation}  `)}${indentation}${braces[1]}`;
   }
   // Line up all entries on a single line in case the entries do not exceed
   // `breakLength`.
   if (isBelowBreakLength(ctx, output, 0, base)) {
-    return `${braces[0]}${base ? ` ${base}` : ''} ${join(output, ', ')} ` +
+    return `${braces[0]}${base ? ` ${base}` : ''} ${ArrayPrototypeJoin(output, ', ')} ` +
       braces[1];
   }
   const indentation = StringPrototypeRepeat(' ', ctx.indentationLvl);
@@ -2083,7 +2082,7 @@ function reduceToSingleString(
   const ln = base === '' && braces[0].length === 1 ?
     ' ' : `${base ? ` ${base}` : ''}\n${indentation}  `;
   // Line up each entry on an individual line.
-  return `${braces[0]}${ln}${join(output, `,\n${indentation}  `)} ${braces[1]}`;
+  return `${braces[0]}${ln}${ArrayPrototypeJoin(output, `,\n${indentation}  `)} ${braces[1]}`;
 }
 
 function hasBuiltInToString(value) {