diff --git a/lib/api/readable.js b/lib/api/readable.js
index 5ebd04ebe83..0c4ec9e5247 100644
--- a/lib/api/readable.js
+++ b/lib/api/readable.js
@@ -1,6 +1,7 @@
 'use strict'
 
 const assert = require('node:assert')
+const { StringDecoder } = require('node:string_decoder')
 const { addAbortListener } = require('node:events')
 const { Readable } = require('node:stream')
 const { RequestAbortedError, NotSupportedError, InvalidArgumentError, AbortError } = require('../core/errors')
@@ -326,6 +327,9 @@ class BodyReadable extends Readable {
   setEncoding (encoding) {
     if (Buffer.isEncoding(encoding)) {
       this._readableState.encoding = encoding
+      if (this[kConsume]) {
+        this[kConsume].decoder = new StringDecoder(encoding)
+      }
     }
     return this
   }
@@ -546,8 +550,14 @@ function consumeEnd (consume, encoding) {
  * @returns {void}
  */
 function consumePush (consume, chunk) {
-  consume.length += chunk.length
-  consume.body.push(chunk)
+  if (consume.decoder) {
+    const string = consume.decoder.write(chunk)
+    consume.length += Buffer.byteLength(string)
+    consume.body.push(string)
+  } else {
+    consume.length += chunk.length
+    consume.body.push(chunk)
+  }
 }
 
 /**