diff --git a/lib/web/websocket/connection.js b/lib/web/websocket/connection.js
index 45f68e1de93..4bab0190731 100644
--- a/lib/web/websocket/connection.js
+++ b/lib/web/websocket/connection.js
@@ -7,7 +7,7 @@ const {
   kByteParser,
   kReceivedClose
 } = require('./symbols')
-const { fireEvent, failWebsocketConnection } = require('./util')
+const { fireEvent, failWebsocketConnection, hasSentClosingHandshake } = require('./util')
 const { channels } = require('../../core/diagnostics')
 const { CloseEvent } = require('./events')
 const { makeRequest } = require('../fetch/request')
@@ -239,7 +239,7 @@ function onSocketClose () {
   if (result) {
     code = result.code ?? 1005
     reason = result.reason
-  } else if (!ws[kSentClose]) {
+  } else if (!hasSentClosingHandshake(ws)) {
     // If _The WebSocket
     // Connection is Closed_ and no Close control frame was received by the
     // endpoint (such as could occur if the underlying transport connection
diff --git a/lib/web/websocket/receiver.js b/lib/web/websocket/receiver.js
index 18dc474f16e..d4440bd2ed1 100644
--- a/lib/web/websocket/receiver.js
+++ b/lib/web/websocket/receiver.js
@@ -4,7 +4,7 @@ const { Writable } = require('node:stream')
 const { parserStates, opcodes, states, emptyBuffer } = require('./constants')
 const { kReadyState, kSentClose, kResponse, kReceivedClose } = require('./symbols')
 const { channels } = require('../../core/diagnostics')
-const { isValidStatusCode, failWebsocketConnection, websocketMessageReceived } = require('./util')
+const { isValidStatusCode, failWebsocketConnection, websocketMessageReceived, hasSentClosingHandshake } = require('./util')
 const { WebsocketFrameSend } = require('./frame')
 
 // This code was influenced by ws released under the MIT license.
@@ -104,7 +104,7 @@ class ByteParser extends Writable {
 
           this.#info.closeInfo = this.parseCloseBody(false, body)
 
-          if (!this.ws[kSentClose]) {
+          if (!hasSentClosingHandshake(this.ws)) {
             // If an endpoint receives a Close frame and did not previously send a
             // Close frame, the endpoint MUST send a Close frame in response.  (When
             // sending a Close frame in response, the endpoint typically echos the
diff --git a/lib/web/websocket/util.js b/lib/web/websocket/util.js
index 8abe73c83e3..9f0a0c1ded5 100644
--- a/lib/web/websocket/util.js
+++ b/lib/web/websocket/util.js
@@ -1,6 +1,6 @@
 'use strict'
 
-const { kReadyState, kController, kResponse, kBinaryType, kWebSocketURL } = require('./symbols')
+const { kReadyState, kController, kResponse, kBinaryType, kWebSocketURL, kSentClose } = require('./symbols')
 const { states, opcodes } = require('./constants')
 const { MessageEvent, ErrorEvent } = require('./events')
 
@@ -8,6 +8,7 @@ const { MessageEvent, ErrorEvent } = require('./events')
 
 /**
  * @param {import('./websocket').WebSocket} ws
+ * @returns {boolean}
  */
 function isEstablished (ws) {
   // If the server's response is validated as provided for above, it is
@@ -18,6 +19,7 @@ function isEstablished (ws) {
 
 /**
  * @param {import('./websocket').WebSocket} ws
+ * @returns {boolean}
  */
 function isClosing (ws) {
   // Upon either sending or receiving a Close control frame, it is said
@@ -28,6 +30,15 @@ function isClosing (ws) {
 
 /**
  * @param {import('./websocket').WebSocket} ws
+ * @returns {boolean}
+ */
+function hasSentClosingHandshake (ws) {
+  return ws[kSentClose] === true
+}
+
+/**
+ * @param {import('./websocket').WebSocket} ws
+ * @returns {boolean}
  */
 function isClosed (ws) {
   return ws[kReadyState] === states.CLOSED
@@ -193,6 +204,7 @@ module.exports = {
   isEstablished,
   isClosing,
   isClosed,
+  hasSentClosingHandshake,
   fireEvent,
   isValidSubprotocol,
   isValidStatusCode,
diff --git a/lib/web/websocket/websocket.js b/lib/web/websocket/websocket.js
index 0072da48193..b4d2c82fe80 100644
--- a/lib/web/websocket/websocket.js
+++ b/lib/web/websocket/websocket.js
@@ -13,7 +13,7 @@ const {
   kSentClose,
   kByteParser
 } = require('./symbols')
-const { isEstablished, isClosing, isValidSubprotocol, failWebsocketConnection, fireEvent } = require('./util')
+const { isEstablished, isClosing, isValidSubprotocol, failWebsocketConnection, fireEvent, isClosed, hasSentClosingHandshake } = require('./util')
 const { establishWebSocketConnection } = require('./connection')
 const { WebsocketFrameSend } = require('./frame')
 const { ByteParser } = require('./receiver')
@@ -184,7 +184,7 @@ class WebSocket extends EventTarget {
     }
 
     // 3. Run the first matching steps from the following list:
-    if (this[kReadyState] === WebSocket.CLOSING || this[kReadyState] === WebSocket.CLOSED) {
+    if (isClosing(this) || isClosed(this)) {
       // If this's ready state is CLOSING (2) or CLOSED (3)
       // Do nothing.
     } else if (!isEstablished(this)) {
@@ -193,7 +193,7 @@ class WebSocket extends EventTarget {
       // to CLOSING (2).
       failWebsocketConnection(this, 'Connection was closed before it was established.')
       this[kReadyState] = WebSocket.CLOSING
-    } else if (!isClosing(this)) {
+    } else if (!(hasSentClosingHandshake(this))) {
       // If the WebSocket closing handshake has not yet been started
       // Start the WebSocket closing handshake and set this's ready
       // state to CLOSING (2).