diff --git a/src/node/proxy.ts b/src/node/proxy.ts
index 2d9056996..1377048b9 100644
--- a/src/node/proxy.ts
+++ b/src/node/proxy.ts
@@ -1,5 +1,6 @@
 import * as cookie from "cookie"
 import type { Request } from "express"
+import http from "http"
 import proxyServer from "http-proxy"
 import { getCookieSessionName, HttpCode } from "../common/http"
 
@@ -26,7 +27,7 @@ function identity<T>(val: T): T {
 
 // Strip the code-server cookie if it exists to avoid transmitting the cookie
 // to potentially malicious local ports.
-proxy.on("proxyReq", (preq, req) => {
+function stripCookie(preq: http.ClientRequest, req: http.IncomingMessage) {
   if (req.headers.cookie) {
     const cookieSessionName = getCookieSessionName((req as Request).args["cookie-suffix"])
     // Encoding and decoding are no-ops; we just want to remove the token
@@ -45,7 +46,10 @@ proxy.on("proxyReq", (preq, req) => {
       ),
     )
   }
-})
+}
+
+proxy.on("proxyReq", stripCookie)
+proxy.on("proxyReqWs", stripCookie)
 
 // Intercept the response to rewrite absolute redirects against the base path.
 // Is disabled when the request has no base path which means /absproxy is in use.
diff --git a/test/unit/node/proxy.test.ts b/test/unit/node/proxy.test.ts
index 4c3320a07..3807fe77e 100644
--- a/test/unit/node/proxy.test.ts
+++ b/test/unit/node/proxy.test.ts
@@ -303,6 +303,13 @@ describe("proxy", () => {
       res.end(req.headers.cookie)
     })
 
+    wsRouter.ws("/wsup/cookies", async (req) => {
+      wss.handleUpgrade(req, req.ws, req.head, (ws) => {
+        ws.on("message", () => ws.send(req.headers.cookie || ""))
+        req.ws.resume()
+      })
+    })
+
     const cookies = [
       "cookie2=hello",
       // Cookies should pass through unchanged, neither encoded nor decoded.
@@ -316,13 +323,22 @@ describe("proxy", () => {
     for (let i = 0; i <= cookies.length; ++i) {
       const left = cookies.slice(0, i)
       const right = cookies.slice(i)
-      const resp = await codeServer.fetch(proxyPath + "/cookies", {
-        headers: {
-          cookie: [...left, `code-server-session=${token}`, ...right].join("; "),
-        },
-      })
+      const expected = cookies.join("; ")
+      const headers = {
+        cookie: [...left, `code-server-session=${token}`, ...right].join("; "),
+      }
+      // Regular HTTP request.
+      const resp = await codeServer.fetch(proxyPath + "/cookies", { headers })
       expect(resp.status).toBe(200)
-      expect(await resp.text()).toBe(cookies.join("; "))
+      expect(await resp.text()).toBe(expected)
+      // Web socket request.
+      const ws = await codeServer.wsWait(proxyPath + "/cookies", { headers })
+      const got = await new Promise((resolve) => {
+        ws.send("init")
+        ws.on("message", (msg) => resolve(msg))
+      })
+      ws.terminate()
+      expect(got).toBe(expected)
     }
   })