diff --git a/lib/web/fetch/constants.js b/lib/web/fetch/constants.js
index dad8d0b5776..1f285e06283 100644
--- a/lib/web/fetch/constants.js
+++ b/lib/web/fetch/constants.js
@@ -1,27 +1,30 @@
 'use strict'
 
-const corsSafeListedMethods = ['GET', 'HEAD', 'POST']
+const corsSafeListedMethods = /** @type {const} */ (['GET', 'HEAD', 'POST'])
 const corsSafeListedMethodsSet = new Set(corsSafeListedMethods)
 
-const nullBodyStatus = [101, 204, 205, 304]
+const nullBodyStatus = /** @type {const} */ ([101, 204, 205, 304])
 
-const redirectStatus = [301, 302, 303, 307, 308]
+const redirectStatus = /** @type {const} */ ([301, 302, 303, 307, 308])
 const redirectStatusSet = new Set(redirectStatus)
 
-// https://fetch.spec.whatwg.org/#block-bad-port
-const badPorts = [
+/**
+ * @see https://fetch.spec.whatwg.org/#block-bad-port
+ */
+const badPorts = /** @type {const} */ ([
   '1', '7', '9', '11', '13', '15', '17', '19', '20', '21', '22', '23', '25', '37', '42', '43', '53', '69', '77', '79',
   '87', '95', '101', '102', '103', '104', '109', '110', '111', '113', '115', '117', '119', '123', '135', '137',
   '139', '143', '161', '179', '389', '427', '465', '512', '513', '514', '515', '526', '530', '531', '532',
   '540', '548', '554', '556', '563', '587', '601', '636', '989', '990', '993', '995', '1719', '1720', '1723',
   '2049', '3659', '4045', '4190', '5060', '5061', '6000', '6566', '6665', '6666', '6667', '6668', '6669', '6679',
   '6697', '10080'
-]
-
+])
 const badPortsSet = new Set(badPorts)
 
-// https://w3c.github.io/webappsec-referrer-policy/#referrer-policies
-const referrerPolicy = [
+/**
+ * @see https://w3c.github.io/webappsec-referrer-policy/#referrer-policies
+ */
+const referrerPolicy = /** @type {const} */ ([
   '',
   'no-referrer',
   'no-referrer-when-downgrade',
@@ -31,29 +34,31 @@ const referrerPolicy = [
   'origin-when-cross-origin',
   'strict-origin-when-cross-origin',
   'unsafe-url'
-]
+])
 const referrerPolicySet = new Set(referrerPolicy)
 
-const requestRedirect = ['follow', 'manual', 'error']
+const requestRedirect = /** @type {const} */ (['follow', 'manual', 'error'])
 
-const safeMethods = ['GET', 'HEAD', 'OPTIONS', 'TRACE']
+const safeMethods = /** @type {const} */ (['GET', 'HEAD', 'OPTIONS', 'TRACE'])
 const safeMethodsSet = new Set(safeMethods)
 
-const requestMode = ['navigate', 'same-origin', 'no-cors', 'cors']
+const requestMode = /** @type {const} */ (['navigate', 'same-origin', 'no-cors', 'cors'])
 
-const requestCredentials = ['omit', 'same-origin', 'include']
+const requestCredentials = /** @type {const} */ (['omit', 'same-origin', 'include'])
 
-const requestCache = [
+const requestCache = /** @type {const} */ ([
   'default',
   'no-store',
   'reload',
   'no-cache',
   'force-cache',
   'only-if-cached'
-]
+])
 
-// https://fetch.spec.whatwg.org/#request-body-header-name
-const requestBodyHeader = [
+/**
+ * @see https://fetch.spec.whatwg.org/#request-body-header-name
+ */
+const requestBodyHeader = /** @type {const} */ ([
   'content-encoding',
   'content-language',
   'content-location',
@@ -63,18 +68,22 @@ const requestBodyHeader = [
   // removed in the Headers implementation. However, undici doesn't
   // filter out headers, so we add it here.
   'content-length'
-]
+])
 
-// https://fetch.spec.whatwg.org/#enumdef-requestduplex
-const requestDuplex = [
+/**
+ * @see https://fetch.spec.whatwg.org/#enumdef-requestduplex
+ */
+const requestDuplex = /** @type {const} */ ([
   'half'
-]
+])
 
-// http://fetch.spec.whatwg.org/#forbidden-method
-const forbiddenMethods = ['CONNECT', 'TRACE', 'TRACK']
+/**
+ * @see http://fetch.spec.whatwg.org/#forbidden-method
+ */
+const forbiddenMethods = /** @type {const} */ (['CONNECT', 'TRACE', 'TRACK'])
 const forbiddenMethodsSet = new Set(forbiddenMethods)
 
-const subresource = [
+const subresource = /** @type {const} */ ([
   'audio',
   'audioworklet',
   'font',
@@ -87,7 +96,7 @@ const subresource = [
   'video',
   'xslt',
   ''
-]
+])
 const subresourceSet = new Set(subresource)
 
 module.exports = {