diff --git a/lib/web/fetch/formdata-parser.js b/lib/web/fetch/formdata-parser.js
index b889fbf898d..843a6ce518f 100644
--- a/lib/web/fetch/formdata-parser.js
+++ b/lib/web/fetch/formdata-parser.js
@@ -444,15 +444,13 @@ function parseMultipartFormDataName (input, position) {
  * @param {{ position: number }} position
  */
 function collectASequenceOfBytes (condition, input, position) {
-  const result = []
+  let start = position.position
 
-  while (position.position < input.length && condition(input[position.position])) {
-    result.push(input[position.position])
-
-    position.position++
+  while (start < input.length && condition(input[start])) {
+    ++start
   }
 
-  return Buffer.from(result, result.length)
+  return input.subarray(position.position, (position.position = start))
 }
 
 /**