diff --git a/lib/web/fetch/body.js b/lib/web/fetch/body.js
index 899f2216f90..83426cd586a 100644
--- a/lib/web/fetch/body.js
+++ b/lib/web/fetch/body.js
@@ -496,14 +496,14 @@ function parseJSONFromBytes (bytes) {
 
 /**
  * @see https://fetch.spec.whatwg.org/#concept-body-mime-type
- * @param {any} object internal state
+ * @param {any} requestOrResponse internal state
  */
-function bodyMimeType (object) {
+function bodyMimeType (requestOrResponse) {
   // 1. Let headers be null.
   // 2. If requestOrResponse is a Request object, then set headers to requestOrResponse’s request’s header list.
   // 3. Otherwise, set headers to requestOrResponse’s response’s header list.
   /** @type {import('./headers').HeadersList} */
-  const headers = object.headersList
+  const headers = requestOrResponse.headersList
 
   // 4. Let mimeType be the result of extracting a MIME type from headers.
   const mimeType = extractMimeType(headers)
diff --git a/lib/web/fetch/headers.js b/lib/web/fetch/headers.js
index 1092ba7b8fe..39648ad1d02 100644
--- a/lib/web/fetch/headers.js
+++ b/lib/web/fetch/headers.js
@@ -13,9 +13,6 @@ const { webidl } = require('./webidl')
 const assert = require('node:assert')
 const util = require('node:util')
 
-// TODO(@KhafraDev): remove
-const kHeadersSortedMap = Symbol('headers map sorted')
-
 /**
  * @param {number} code
  */
@@ -119,6 +116,67 @@ function appendHeader (headers, name, value) {
   //    privileged no-CORS request headers from headers
 }
 
+// https://fetch.spec.whatwg.org/#concept-header-list-sort-and-combine
+/**
+ * @param {Headers} target
+ */
+function headersListSortAndCombine (target) {
+  const headersList = getHeadersList(target)
+
+  if (!headersList) {
+    return []
+  }
+
+  if (headersList.sortedMap) {
+    return headersList.sortedMap
+  }
+
+  // 1. Let headers be an empty list of headers with the key being the name
+  //    and value the value.
+  const headers = []
+
+  // 2. Let names be the result of convert header names to a sorted-lowercase
+  //    set with all the names of the headers in list.
+  const names = headersList.toSortedArray()
+
+  const cookies = headersList.cookies
+
+  // fast-path
+  if (cookies === null || cookies.length === 1) {
+    // Note: The non-null assertion of value has already been done by `HeadersList#toSortedArray`
+    return (headersList.sortedMap = names)
+  }
+
+  // 3. For each name of names:
+  for (let i = 0; i < names.length; ++i) {
+    const { 0: name, 1: value } = names[i]
+    // 1. If name is `set-cookie`, then:
+    if (name === 'set-cookie') {
+      // 1. Let values be a list of all values of headers in list whose name
+      //    is a byte-case-insensitive match for name, in order.
+
+      // 2. For each value of values:
+      // 1. Append (name, value) to headers.
+      for (let j = 0; j < cookies.length; ++j) {
+        headers.push([name, cookies[j]])
+      }
+    } else {
+      // 2. Otherwise:
+
+      // 1. Let value be the result of getting name from list.
+
+      // 2. Assert: value is non-null.
+      // Note: This operation was done by `HeadersList#toSortedArray`.
+
+      // 3. Append (name, value) to headers.
+      headers.push([name, value])
+    }
+  }
+
+  // 4. Return headers.
+  return (headersList.sortedMap = headers)
+}
+
 function compareHeaderName (a, b) {
   return a[0] < b[0] ? -1 : 1
 }
@@ -548,58 +606,6 @@ class Headers {
     return []
   }
 
-  // https://fetch.spec.whatwg.org/#concept-header-list-sort-and-combine
-  get [kHeadersSortedMap] () {
-    if (this.#headersList.sortedMap) {
-      return this.#headersList.sortedMap
-    }
-
-    // 1. Let headers be an empty list of headers with the key being the name
-    //    and value the value.
-    const headers = []
-
-    // 2. Let names be the result of convert header names to a sorted-lowercase
-    //    set with all the names of the headers in list.
-    const names = this.#headersList.toSortedArray()
-
-    const cookies = this.#headersList.cookies
-
-    // fast-path
-    if (cookies === null || cookies.length === 1) {
-      // Note: The non-null assertion of value has already been done by `HeadersList#toSortedArray`
-      return (this.#headersList.sortedMap = names)
-    }
-
-    // 3. For each name of names:
-    for (let i = 0; i < names.length; ++i) {
-      const { 0: name, 1: value } = names[i]
-      // 1. If name is `set-cookie`, then:
-      if (name === 'set-cookie') {
-        // 1. Let values be a list of all values of headers in list whose name
-        //    is a byte-case-insensitive match for name, in order.
-
-        // 2. For each value of values:
-        // 1. Append (name, value) to headers.
-        for (let j = 0; j < cookies.length; ++j) {
-          headers.push([name, cookies[j]])
-        }
-      } else {
-        // 2. Otherwise:
-
-        // 1. Let value be the result of getting name from list.
-
-        // 2. Assert: value is non-null.
-        // Note: This operation was done by `HeadersList#toSortedArray`.
-
-        // 3. Append (name, value) to headers.
-        headers.push([name, value])
-      }
-    }
-
-    // 4. Return headers.
-    return (this.#headersList.sortedMap = headers)
-  }
-
   [util.inspect.custom] (depth, options) {
     options.depth ??= depth
 
@@ -614,6 +620,9 @@ class Headers {
     o.#guard = guard
   }
 
+  /**
+   * @param {Headers} o
+   */
   static getHeadersList (o) {
     return o.#headersList
   }
@@ -629,7 +638,7 @@ Reflect.deleteProperty(Headers, 'setHeadersGuard')
 Reflect.deleteProperty(Headers, 'getHeadersList')
 Reflect.deleteProperty(Headers, 'setHeadersList')
 
-iteratorMixin('Headers', Headers, kHeadersSortedMap, 0, 1)
+iteratorMixin('Headers', Headers, headersListSortAndCombine, 0, 1)
 
 Object.defineProperties(Headers.prototype, {
   append: kEnumerableProperty,
diff --git a/lib/web/fetch/util.js b/lib/web/fetch/util.js
index b85e754a1d9..daa2483c943 100644
--- a/lib/web/fetch/util.js
+++ b/lib/web/fetch/util.js
@@ -825,7 +825,7 @@ const esIteratorPrototype = Object.getPrototypeOf(Object.getPrototypeOf([][Symbo
 /**
  * @see https://webidl.spec.whatwg.org/#dfn-iterator-prototype-object
  * @param {string} name name of the instance
- * @param {symbol|((target: any) => any)} kInternalIterator
+ * @param {((target: any) => any)} kInternalIterator
  * @param {string | number} [keyIndex]
  * @param {string | number} [valueIndex]
  */
@@ -867,7 +867,7 @@ function createIterator (name, kInternalIterator, keyIndex = 0, valueIndex = 1)
       // 7. Let kind be object’s kind.
       // 8. Let values be object’s target's value pairs to iterate over.
       const index = this.#index
-      const values = typeof kInternalIterator === 'symbol' ? this.#target[kInternalIterator] : kInternalIterator(this.#target)
+      const values = kInternalIterator(this.#target)
 
       // 9. Let len be the length of values.
       const len = values.length
@@ -961,7 +961,7 @@ function createIterator (name, kInternalIterator, keyIndex = 0, valueIndex = 1)
  * @see https://webidl.spec.whatwg.org/#dfn-iterator-prototype-object
  * @param {string} name name of the instance
  * @param {any} object class
- * @param {symbol} kInternalIterator
+ * @param {(target: any) => any} kInternalIterator
  * @param {string | number} [keyIndex]
  * @param {string | number} [valueIndex]
  */
diff --git a/test/fetch/spread.js b/test/fetch/spread.js
index f684cb18f40..ca05bea6e2a 100644
--- a/test/fetch/spread.js
+++ b/test/fetch/spread.js
@@ -3,6 +3,7 @@
 const undici = require('../..')
 const { test } = require('node:test')
 const assert = require('node:assert')
+const { inspect } = require('node:util')
 
 test('spreading web classes yields empty objects', (t) => {
   for (const object of [
@@ -13,3 +14,28 @@ test('spreading web classes yields empty objects', (t) => {
     assert.deepStrictEqual({ ...object }, {})
   }
 })
+
+test('Objects only have an expected set of symbols on their prototypes', (t) => {
+  const allowedSymbols = [
+    Symbol.iterator,
+    Symbol.toStringTag,
+    inspect.custom
+  ]
+
+  for (const object of [
+    undici.FormData,
+    undici.Response,
+    undici.Request,
+    undici.Headers,
+    undici.WebSocket,
+    undici.MessageEvent,
+    undici.CloseEvent,
+    undici.ErrorEvent,
+    undici.EventSource
+  ]) {
+    const symbols = Object.keys(Object.getOwnPropertyDescriptors(object.prototype))
+      .filter(v => typeof v === 'symbol')
+
+    assert(symbols.every(symbol => allowedSymbols.includes(symbol)))
+  }
+})
diff --git a/test/wpt/runner/worker.mjs b/test/wpt/runner/worker.mjs
index fd87189c1ee..b4fea2ccf85 100644
--- a/test/wpt/runner/worker.mjs
+++ b/test/wpt/runner/worker.mjs
@@ -5,15 +5,20 @@ import { setFlagsFromString } from 'node:v8'
 import { runInNewContext, runInThisContext } from 'node:vm'
 import { parentPort, workerData } from 'node:worker_threads'
 import {
-  fetch, FormData, Headers, Request, Response, setGlobalOrigin
+  fetch,
+  FormData,
+  Headers,
+  Request,
+  Response,
+  setGlobalOrigin,
+  CloseEvent,
+  WebSocket,
+  caches,
+  EventSource
 } from '../../../index.js'
-import { CloseEvent } from '../../../lib/web/websocket/events.js'
-import { WebSocket } from '../../../lib/web/websocket/websocket.js'
+// TODO(@KhafraDev): export these in index.js
 import { Cache } from '../../../lib/web/cache/cache.js'
 import { CacheStorage } from '../../../lib/web/cache/cachestorage.js'
-import { kConstruct } from '../../../lib/web/cache/symbols.js'
-// TODO(@KhafraDev): move this import once its added to index
-import { EventSource } from '../../../lib/web/eventsource/eventsource.js'
 import { webcrypto } from 'node:crypto'
 
 const { initScripts, meta, test, url, path } = workerData
@@ -79,7 +84,7 @@ Object.defineProperties(globalThis, {
   },
   caches: {
     ...globalPropertyDescriptors,
-    value: new CacheStorage(kConstruct)
+    value: caches
   },
   Cache: {
     ...globalPropertyDescriptors,