diff --git a/lib/contrib/yeast.ts b/lib/contrib/yeast.ts
deleted file mode 100644
index 71ad33eaf..000000000
--- a/lib/contrib/yeast.ts
+++ /dev/null
@@ -1,62 +0,0 @@
-// imported from https://github.com/unshiftio/yeast
-'use strict';
-
-const alphabet = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_'.split('')
-    , length = 64
-    , map = {};
-let seed = 0
-    , i = 0
-    , prev;
-
-/**
- * Return a string representing the specified number.
- *
- * @param {Number} num The number to convert.
- * @returns {String} The string representation of the number.
- * @api public
- */
-export function encode(num) {
-    let encoded = '';
-
-    do {
-        encoded = alphabet[num % length] + encoded;
-        num = Math.floor(num / length);
-    } while (num > 0);
-
-    return encoded;
-}
-
-/**
- * Return the integer value specified by the given string.
- *
- * @param {String} str The string to convert.
- * @returns {Number} The integer value represented by the string.
- * @api public
- */
-export function decode(str) {
-    let decoded = 0;
-
-    for (i = 0; i < str.length; i++) {
-        decoded = decoded * length + map[str.charAt(i)];
-    }
-
-    return decoded;
-}
-
-/**
- * Yeast: A tiny growing id generator.
- *
- * @returns {String} A unique id.
- * @api public
- */
-export function yeast() {
-    const now = encode(+new Date());
-
-    if (now !== prev) return seed = 0, prev = now;
-    return now +'.'+ encode(seed++);
-}
-
-//
-// Map each character to its index.
-//
-for (; i < length; i++) map[alphabet[i]] = i;
diff --git a/lib/transports/polling.ts b/lib/transports/polling.ts
index 12e270ffd..2f09e8021 100644
--- a/lib/transports/polling.ts
+++ b/lib/transports/polling.ts
@@ -1,5 +1,5 @@
 import { Transport } from "../transport.js";
-import { yeast } from "../contrib/yeast.js";
+import { randomString } from "../util.js";
 import { encodePayload, decodePayload } from "engine.io-parser";
 import debugModule from "debug"; // debug()
 
@@ -164,7 +164,7 @@ export abstract class Polling extends Transport {
 
     // cache busting is forced
     if (false !== this.opts.timestampRequests) {
-      query[this.opts.timestampParam] = yeast();
+      query[this.opts.timestampParam] = randomString();
     }
 
     if (!this.supportsBinary && !query.sid) {
diff --git a/lib/transports/websocket.ts b/lib/transports/websocket.ts
index 7e4a0a9ce..d8b1d9505 100644
--- a/lib/transports/websocket.ts
+++ b/lib/transports/websocket.ts
@@ -1,6 +1,5 @@
 import { Transport } from "../transport.js";
-import { yeast } from "../contrib/yeast.js";
-import { pick } from "../util.js";
+import { pick, randomString } from "../util.js";
 import { encodePacket } from "engine.io-parser";
 import type { Packet, RawData } from "engine.io-parser";
 import { globalThisShim as globalThis, nextTick } from "../globals.node.js";
@@ -140,7 +139,7 @@ export abstract class BaseWS extends Transport {
 
     // append timestamp to URI
     if (this.opts.timestampRequests) {
-      query[this.opts.timestampParam] = yeast();
+      query[this.opts.timestampParam] = randomString();
     }
 
     // communicate binary support capabilities
diff --git a/lib/util.ts b/lib/util.ts
index e918e2b7c..bfb6a59aa 100644
--- a/lib/util.ts
+++ b/lib/util.ts
@@ -53,3 +53,13 @@ function utf8Length(str) {
   }
   return length;
 }
+
+/**
+ * Generates a random 8-characters string.
+ */
+export function randomString() {
+  return (
+    Date.now().toString(36).substring(3) +
+    Math.random().toString(36).substring(2, 5)
+  );
+}
diff --git a/test/engine.io-client.js b/test/engine.io-client.js
index b4a290043..7f526afd4 100644
--- a/test/engine.io-client.js
+++ b/test/engine.io-client.js
@@ -1,5 +1,6 @@
 const expect = require("expect.js");
 const { Socket, protocol } = require("..");
+const { randomString } = require("../build/cjs/util.js");
 
 const expectedPort =
   typeof location !== "undefined" && "https:" === location.protocol
@@ -99,4 +100,14 @@ describe("engine.io-client", () => {
     expect(client.hostname).to.be("::1");
     expect(client.port).to.be(expectedPort);
   });
+
+  it("should generate a random string", () => {
+    const a = randomString();
+    const b = randomString();
+    const c = randomString();
+
+    expect(a.length).to.eql(8);
+    expect(a).to.not.equal(b);
+    expect(b).to.not.equal(c);
+  });
 });