diff --git a/lib/utils/util.js b/lib/utils/util.js
index 7e3b4a28..0ab6d5c4 100644
--- a/lib/utils/util.js
+++ b/lib/utils/util.js
@@ -96,31 +96,19 @@ util.time = function time(date) {
 
 /**
  * Reverse a hex-string.
- * @param {String} str - Hex string.
+ * @param {Buffer}
  * @returns {String} Reversed hex string.
  */
 
 util.revHex = function revHex(buf) {
   assert(Buffer.isBuffer(buf));
 
-  const str = buf.toString('hex');
-
-  let out = '';
-
-  for (let i = str.length - 2; i >= 0; i -= 2)
-    out += str[i] + str[i + 1];
-
-  return out;
+  return Buffer.from(buf).reverse().toString('hex');
 };
 
 util.fromRev = function fromRev(str) {
   assert(typeof str === 'string');
   assert((str.length & 1) === 0);
 
-  let out = '';
-
-  for (let i = str.length - 2; i >= 0; i -= 2)
-    out += str[i] + str[i + 1];
-
-  return Buffer.from(out, 'hex');
+  return Buffer.from(str, 'hex').reverse();
 };