diff --git a/package.json b/package.json
index 846a8ca6d9..b629e8e08e 100644
--- a/package.json
+++ b/package.json
@@ -190,7 +190,6 @@
         "@types/escape-html": "^1.0.1",
         "@types/express": "^5.0.0",
         "@types/file-saver": "^2.0.3",
-        "@types/fs-extra": "^11.0.0",
         "@types/glob-to-regexp": "^0.4.1",
         "@types/jest": "29.5.12",
         "@types/jitsi-meet": "^2.0.2",
@@ -242,7 +241,6 @@
         "fetch-mock": "9.11.0",
         "fetch-mock-jest": "^1.5.1",
         "file-loader": "^6.0.0",
-        "fs-extra": "^11.0.0",
         "glob": "^11.0.0",
         "html-webpack-plugin": "^5.5.3",
         "husky": "^9.0.0",
diff --git a/playwright/e2e/login/utils.ts b/playwright/e2e/login/utils.ts
index ae794bd911..dffa6ad7be 100644
--- a/playwright/e2e/login/utils.ts
+++ b/playwright/e2e/login/utils.ts
@@ -6,10 +6,9 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import { Page, expect, Fixtures } from "@playwright/test";
+import { Page, expect } from "@playwright/test";
 
 import { Credentials, HomeserverInstance } from "../../plugins/homeserver";
-import { Services } from "../../services.ts";
 
 /** Visit the login page, choose to log in with "OAuth test", register a new account, and redirect back to Element
  */
diff --git a/playwright/plugins/utils/object.ts b/playwright/plugins/utils/object.ts
new file mode 100644
index 0000000000..bfb92fecec
--- /dev/null
+++ b/playwright/plugins/utils/object.ts
@@ -0,0 +1,16 @@
+/*
+Copyright 2024 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
+Please see LICENSE files in the repository root for full details.
+*/
+
+/**
+ * Deep copy the given object. The object MUST NOT have circular references and
+ * MUST NOT have functions.
+ * @param obj - The object to deep copy.
+ * @returns A copy of the object without any references to the original.
+ */
+export function deepCopy<T>(obj: T): T {
+    return JSON.parse(JSON.stringify(obj));
+}
diff --git a/playwright/testcontainers/dendrite.ts b/playwright/testcontainers/dendrite.ts
index e073fbcada..006e7d6b94 100644
--- a/playwright/testcontainers/dendrite.ts
+++ b/playwright/testcontainers/dendrite.ts
@@ -8,12 +8,12 @@ Please see LICENSE files in the repository root for full details.
 import { GenericContainer, Wait } from "testcontainers";
 import { APIRequestContext } from "@playwright/test";
 import * as YAML from "yaml";
-import { deepCopy } from "matrix-js-sdk/src/utils";
 import { set } from "lodash";
 
 import { getFreePort } from "../plugins/utils/port.ts";
 import { randB64Bytes } from "../plugins/utils/rand.ts";
 import { StartedSynapseContainer } from "./synapse.ts";
+import { deepCopy } from "../plugins/utils/object.ts";
 
 const DEFAULT_CONFIG = {
     version: 2,
diff --git a/playwright/testcontainers/mas.ts b/playwright/testcontainers/mas.ts
index b4e5bf7537..f2cdef6794 100644
--- a/playwright/testcontainers/mas.ts
+++ b/playwright/testcontainers/mas.ts
@@ -5,13 +5,11 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import { AbstractStartedContainer, GenericContainer, StartedTestContainer, Wait } from "testcontainers";
-import crypto from "node:crypto";
+import { GenericContainer, StartedTestContainer, Wait } from "testcontainers";
 import * as YAML from "yaml";
 
 import { getFreePort } from "../plugins/utils/port.ts";
-import { Credentials } from "../plugins/homeserver";
-import { deepCopy } from "matrix-js-sdk/src/utils.ts";
+import { deepCopy } from "../plugins/utils/object.ts";
 
 const DEFAULT_CONFIG = {
     http: {
diff --git a/playwright/testcontainers/synapse.ts b/playwright/testcontainers/synapse.ts
index c3cb0ab69f..33a42c1a68 100644
--- a/playwright/testcontainers/synapse.ts
+++ b/playwright/testcontainers/synapse.ts
@@ -9,12 +9,12 @@ import { AbstractStartedContainer, GenericContainer, StartedTestContainer, Wait
 import { APIRequestContext } from "@playwright/test";
 import crypto from "node:crypto";
 import * as YAML from "yaml";
-import { deepCopy } from "matrix-js-sdk/src/utils";
 import { set } from "lodash";
 
 import { getFreePort } from "../plugins/utils/port.ts";
 import { randB64Bytes } from "../plugins/utils/rand.ts";
 import { Credentials, HomeserverInstance } from "../plugins/homeserver";
+import { deepCopy } from "../plugins/utils/object.ts";
 
 const TAG = "develop@sha256:17cc0a301447430624afb860276e5c13270ddeb99a3f6d1c6d519a20b1a8f650";
 
diff --git a/yarn.lock b/yarn.lock
index a68b8cf97a..6697ad9d33 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2939,14 +2939,6 @@
   resolved "https://registry.yarnpkg.com/@types/file-saver/-/file-saver-2.0.7.tgz#8dbb2f24bdc7486c54aa854eb414940bbd056f7d"
   integrity sha512-dNKVfHd/jk0SkR/exKGj2ggkB45MAkzvWCaqLUUgkyjITkGNzH8H+yUwr+BLJUBjZOe9w8X3wgmXhZDRg1ED6A==
 
-"@types/fs-extra@^11.0.0":
-  version "11.0.4"
-  resolved "https://registry.yarnpkg.com/@types/fs-extra/-/fs-extra-11.0.4.tgz#e16a863bb8843fba8c5004362b5a73e17becca45"
-  integrity sha512-yTbItCNreRooED33qjunPthRcSjERP1r4MqCZc7wv0u2sUkzTFp45tgUfS5+r7FrZPdmCCNflLhVSP/o+SemsQ==
-  dependencies:
-    "@types/jsonfile" "*"
-    "@types/node" "*"
-
 "@types/geojson-vt@3.2.5":
   version "3.2.5"
   resolved "https://registry.yarnpkg.com/@types/geojson-vt/-/geojson-vt-3.2.5.tgz#b6c356874991d9ab4207533476dfbcdb21e38408"
@@ -3047,13 +3039,6 @@
   resolved "https://registry.yarnpkg.com/@types/json5/-/json5-0.0.29.tgz#ee28707ae94e11d2b827bcbe5270bcea7f3e71ee"
   integrity sha512-dRLjCWHYg4oaA77cxO64oO+7JwCwnIzkZPdrrC71jQmQtlhM556pwKo5bUzqvZndkVbeFLIIi+9TC40JNF5hNQ==
 
-"@types/jsonfile@*":
-  version "6.1.4"
-  resolved "https://registry.yarnpkg.com/@types/jsonfile/-/jsonfile-6.1.4.tgz#614afec1a1164e7d670b4a7ad64df3e7beb7b702"
-  integrity sha512-D5qGUYwjvnNNextdU59/+fI+spnwtTFmyQP0h+PfIOSkNfpU6AOICUOkm4i0OnSk+NyjdPJrxCDro0sJsWlRpQ==
-  dependencies:
-    "@types/node" "*"
-
 "@types/jsrsasign@^10.5.4":
   version "10.5.15"
   resolved "https://registry.yarnpkg.com/@types/jsrsasign/-/jsrsasign-10.5.15.tgz#5cf1ee506b2fa2435b6e1786a873285c7110eb82"
@@ -6504,15 +6489,6 @@ fs-constants@^1.0.0:
   resolved "https://registry.yarnpkg.com/fs-constants/-/fs-constants-1.0.0.tgz#6be0de9be998ce16af8afc24497b9ee9b7ccd9ad"
   integrity sha512-y6OAwoSIf7FyjMIv94u+b5rdheZEjzR63GTyZJm5qh4Bi+2YgwLCcI/fPFZkL5PSixOt6ZNKm+w+Hfp/Bciwow==
 
-fs-extra@^11.0.0:
-  version "11.2.0"
-  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-11.2.0.tgz#e70e17dfad64232287d01929399e0ea7c86b0e5b"
-  integrity sha512-PmDi3uwK5nFuXh7XDTlVnS17xJS7vW36is2+w3xcv8SVxiB4NyATf4ctkVY5bkSjX0Y4nbvZCq1/EjtEyr9ktw==
-  dependencies:
-    graceful-fs "^4.2.0"
-    jsonfile "^6.0.1"
-    universalify "^2.0.0"
-
 fs.realpath@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
@@ -6798,7 +6774,7 @@ gopd@^1.1.0:
   dependencies:
     get-intrinsic "^1.2.4"
 
-graceful-fs@^4.1.2, graceful-fs@^4.1.6, graceful-fs@^4.2.0, graceful-fs@^4.2.11, graceful-fs@^4.2.4, graceful-fs@^4.2.6, graceful-fs@^4.2.9:
+graceful-fs@^4.1.2, graceful-fs@^4.2.0, graceful-fs@^4.2.11, graceful-fs@^4.2.4, graceful-fs@^4.2.6, graceful-fs@^4.2.9:
   version "4.2.11"
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.2.11.tgz#4183e4e8bf08bb6e05bbb2f7d2e0c8f712ca40e3"
   integrity sha512-RbJ5/jmFcNNCcDV5o9eTnBLJ/HszWV0P73bc+Ff4nS/rJj+YaS6IGyiOL0VoBYX+l1Wrl3k63h/KrH+nhJ0XvQ==
@@ -8129,15 +8105,6 @@ json5@^2.1.2, json5@^2.1.3, json5@^2.2.3:
   resolved "https://registry.yarnpkg.com/json5/-/json5-2.2.3.tgz#78cd6f1a19bdc12b73db5ad0c61efd66c1e29283"
   integrity sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg==
 
-jsonfile@^6.0.1:
-  version "6.1.0"
-  resolved "https://registry.yarnpkg.com/jsonfile/-/jsonfile-6.1.0.tgz#bc55b2634793c679ec6403094eb13698a6ec0aae"
-  integrity sha512-5dgndWOriYSm5cnYaJNhalLNDKOqFwyDB/rr1E9ZsGciGvKPs8R2xYGCacuf3z6K1YKDz182fd+fY3cn3pMqXQ==
-  dependencies:
-    universalify "^2.0.0"
-  optionalDependencies:
-    graceful-fs "^4.1.6"
-
 jsqr@^1.4.0:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/jsqr/-/jsqr-1.4.0.tgz#8efb8d0a7cc6863cb6d95116b9069123ce9eb2d1"
@@ -12062,11 +12029,6 @@ universalify@^0.2.0:
   resolved "https://registry.yarnpkg.com/universalify/-/universalify-0.2.0.tgz#6451760566fa857534745ab1dde952d1b1761be0"
   integrity sha512-CJ1QgKmNg3CwvAv/kOFmtnEN05f0D/cn9QntgNOQlQF9dgvVTHj3t+8JPdjqawCHk7V/KA+fbUqzZ9XWhcqPUg==
 
-universalify@^2.0.0:
-  version "2.0.1"
-  resolved "https://registry.yarnpkg.com/universalify/-/universalify-2.0.1.tgz#168efc2180964e6386d061e094df61afe239b18d"
-  integrity sha512-gptHNQghINnc/vTGIk0SOFGFNXw7JVrlRUtConJRlvaw6DuX0wO5Jeko9sWrMBhh+PsYAZ7oXAiOnf/UKogyiw==
-
 unpipe@1.0.0, unpipe@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/unpipe/-/unpipe-1.0.0.tgz#b2bf4ee8514aae6165b4817829d21b2ef49904ec"