diff --git a/.eslintignore b/.eslintignore
index 08ec761fb3..cfd87467f1 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -1,4 +1,4 @@
-src/vector/modernizr.js
+src/vector/modernizr.cjs
 test/end-to-end-tests/node_modules/
 test/end-to-end-tests/element/
 test/end-to-end-tests/synapse/
diff --git a/.eslintrc.js b/.eslintrc.cjs
similarity index 100%
rename from .eslintrc.js
rename to .eslintrc.cjs
diff --git a/.prettierignore b/.prettierignore
index abaa4d3df3..cade5f84bb 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -21,7 +21,7 @@ electron/pub
 /build_config.yaml
 # Raises an error because it contains a template var breaking the script tag
 src/vector/index.html
-src/vector/modernizr.js
+src/vector/modernizr.cjs
 /docs/lib
 /book
 /debian/tmp
diff --git a/.prettierrc.js b/.prettierrc.js
deleted file mode 100644
index 6a17910f1a..0000000000
--- a/.prettierrc.js
+++ /dev/null
@@ -1 +0,0 @@
-module.exports = require("eslint-plugin-matrix-org/.prettierrc.js");
diff --git a/.stylelintrc.js b/.stylelintrc.cjs
similarity index 100%
rename from .stylelintrc.js
rename to .stylelintrc.cjs
diff --git a/babel.config.js b/babel.config.cjs
similarity index 100%
rename from babel.config.js
rename to babel.config.cjs
diff --git a/jest.config.ts b/jest.config.ts
index 8662a89ca7..b19b884d30 100644
--- a/jest.config.ts
+++ b/jest.config.ts
@@ -43,7 +43,7 @@ const config: Config = {
         "@vector-im/compound-web": "<rootDir>/node_modules/@vector-im/compound-web",
     },
     transformIgnorePatterns: [
-        "/node_modules/(?!(mime|matrix-js-sdk|uuid|p-retry|is-network-error|react-merge-refs|is-ip|ip-regex|super-regex|function-timeout|time-span|convert-hrtime|clone-regexp|is-regexp|matrix-web-i18n|await-lock|@element-hq/web-shared-components|react-virtuoso)).+$",
+        "/node_modules/(?!(mime|matrix-js-sdk|uuid|p-retry|is-network-error|react-merge-refs|is-ip|ip-regex|super-regex|function-timeout|time-span|convert-hrtime|clone-regexp|is-regexp|matrix-web-i18n|await-lock|@element-hq/web-shared-components|react-virtuoso|lodash)).+$",
     ],
     collectCoverageFrom: [
         "<rootDir>/src/**/*.{js,ts,tsx}",
diff --git a/package.json b/package.json
index 8b7efa7942..ae9bae0813 100644
--- a/package.json
+++ b/package.json
@@ -8,6 +8,7 @@
         "url": "https://github.com/element-hq/element-web"
     },
     "license": "SEE LICENSE IN README.md",
+    "type": "module",
     "files": [
         "lib",
         "res",
@@ -40,7 +41,7 @@
         "build-stats": "yarn clean && yarn build:genfiles && yarn build:bundle-stats",
         "build:res": "node scripts/copy-res.ts",
         "build:genfiles": "yarn build:res && yarn build:module_system",
-        "build:modernizr": "modernizr -c .modernizr.json -d src/vector/modernizr.js",
+        "build:modernizr": "modernizr -c .modernizr.json -d src/vector/modernizr.js && mv src/vector/modernizr.js src/vector/modernizr.cjs",
         "build:bundle": "webpack --progress --mode production",
         "build:bundle-stats": "webpack --progress --mode production --json > webpack-stats.json",
         "build:module_system": "node module_system/scripts/install.ts",
@@ -126,7 +127,7 @@
         "linkify-react": "4.3.2",
         "linkify-string": "4.3.2",
         "linkifyjs": "4.3.2",
-        "lodash": "^4.17.21",
+        "lodash": "npm:lodash-es@^4.17.21",
         "maplibre-gl": "^5.0.0",
         "matrix-encrypt-attachment": "^1.0.3",
         "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#develop",
diff --git a/packages/shared-components/package.json b/packages/shared-components/package.json
index fa29558335..91684c1101 100644
--- a/packages/shared-components/package.json
+++ b/packages/shared-components/package.json
@@ -55,7 +55,7 @@
         "@vector-im/compound-design-tokens": "^6.4.3",
         "classnames": "^2.5.1",
         "counterpart": "^0.18.6",
-        "lodash": "^4.17.21",
+        "lodash": "npm:lodash-es@^4.17.21",
         "matrix-web-i18n": "3.6.0",
         "react-merge-refs": "^3.0.2",
         "react-virtuoso": "^4.14.0",
diff --git a/packages/shared-components/yarn.lock b/packages/shared-components/yarn.lock
index f6100b462d..671ae7d10e 100644
--- a/packages/shared-components/yarn.lock
+++ b/packages/shared-components/yarn.lock
@@ -4983,10 +4983,10 @@ lodash.merge@^4.6.2:
   resolved "https://registry.yarnpkg.com/lodash.merge/-/lodash.merge-4.6.2.tgz#558aa53b43b661e1925a0afdfa36a9a1085fe57a"
   integrity sha512-0KpjqXRVvrYyCsX1swR/XTK0va6VQkQM6MNo7PqW77ByjAhoARA8EfrP1N4+KlKj8YS0ZUCtRT/YUuhyYDujIQ==
 
-lodash@^4.17.15, lodash@^4.17.21, lodash@~4.17.15:
+lodash@^4.17.15, lodash@^4.17.21, "lodash@npm:lodash-es@^4.17.21", lodash@~4.17.15:
   version "4.17.23"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.23.tgz#f113b0378386103be4f6893388c73d0bde7f2c5a"
-  integrity sha512-LgVTMpQtIopCi79SJeDiP0TfWi5CNEc/L/aRdTh3yIvmZXTnheWpKjSZhnvMl8iXbC1tFg9gdHHDMLoV7CnG+w==
+  resolved "https://registry.yarnpkg.com/lodash-es/-/lodash-es-4.17.23.tgz#58c4360fd1b5d33afc6c0bbd3d1149349b1138e0"
+  integrity sha512-kVI48u3PZr38HdYz98UmfPnXl2DXrpdctLrFLCd3kOx1xUkOmpFPx7gCWWM5MPkL/fD8zb+Ph0QzjGFs4+hHWg==
 
 long@^5.0.0:
   version "5.3.2"
diff --git a/playwright/e2e/crypto/migration.spec.ts b/playwright/e2e/crypto/migration.spec.ts
index 86072fccc0..191568c29c 100644
--- a/playwright/e2e/crypto/migration.spec.ts
+++ b/playwright/e2e/crypto/migration.spec.ts
@@ -8,9 +8,13 @@ Please see LICENSE files in the repository root for full details.
 
 import path from "path";
 import { readFile } from "node:fs/promises";
+import { dirname } from "node:path";
+import { fileURLToPath } from "node:url";
 
 import { expect, test } from "../../element-web-test";
 
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
 test.describe("migration", { tag: "@no-webkit" }, function () {
     test.use({
         displayName: "Alice",
diff --git a/playwright/e2e/oidc/index.ts b/playwright/e2e/oidc/index.ts
index 50aa2de8d5..2cc6d48176 100644
--- a/playwright/e2e/oidc/index.ts
+++ b/playwright/e2e/oidc/index.ts
@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Com
 Please see LICENSE files in the repository root for full details.
 */
 
-import { type MailpitClient } from "@element-hq/element-web-playwright-common/lib/testcontainers";
+import { type MailpitClient } from "@element-hq/element-web-playwright-common/lib/testcontainers/index.js";
 import { type Page } from "@playwright/test";
 
 import { expect } from "../../element-web-test";
diff --git a/playwright/plugins/homeserver/synapse/consentHomeserver.ts b/playwright/plugins/homeserver/synapse/consentHomeserver.ts
index 9b3316bf57..0dfc0aa735 100644
--- a/playwright/plugins/homeserver/synapse/consentHomeserver.ts
+++ b/playwright/plugins/homeserver/synapse/consentHomeserver.ts
@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Com
 Please see LICENSE files in the repository root for full details.
 */
 
-import { type SynapseContainer } from "@element-hq/element-web-playwright-common/lib/testcontainers";
+import { type SynapseContainer } from "@element-hq/element-web-playwright-common/lib/testcontainers/index.js";
 
 import { type Fixtures } from "../../../element-web-test.ts";
 
diff --git a/playwright/plugins/oauth_server/index.ts b/playwright/plugins/oauth_server/index.ts
index 446426a9c1..16aad2f027 100644
--- a/playwright/plugins/oauth_server/index.ts
+++ b/playwright/plugins/oauth_server/index.ts
@@ -11,6 +11,10 @@ import express from "express";
 import { type AddressInfo } from "net";
 import { type TestInfo } from "@playwright/test";
 import { randB64Bytes } from "@element-hq/element-web-playwright-common/lib/utils/rand.js";
+import { dirname } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
 
 export class OAuthServer {
     private server?: http.Server;
diff --git a/playwright/services.ts b/playwright/services.ts
index 8ecf10e20e..5442a01098 100644
--- a/playwright/services.ts
+++ b/playwright/services.ts
@@ -10,7 +10,7 @@ import {
     type Services as BaseServices,
     type WorkerOptions as BaseWorkerOptions,
 } from "@element-hq/element-web-playwright-common/lib/fixtures";
-import { type HomeserverContainer } from "@element-hq/element-web-playwright-common/lib/testcontainers";
+import { type HomeserverContainer } from "@element-hq/element-web-playwright-common/lib/testcontainers/index.js";
 
 import { type OAuthServer } from "./plugins/oauth_server";
 import { DendriteContainer, PineconeContainer } from "./testcontainers/dendrite";
diff --git a/playwright/testcontainers/dendrite.ts b/playwright/testcontainers/dendrite.ts
index 55938778cd..68a356027e 100644
--- a/playwright/testcontainers/dendrite.ts
+++ b/playwright/testcontainers/dendrite.ts
@@ -14,7 +14,7 @@ import {
     StartedSynapseContainer,
     type HomeserverContainer,
     type StartedMatrixAuthenticationServiceContainer,
-} from "@element-hq/element-web-playwright-common/lib/testcontainers";
+} from "@element-hq/element-web-playwright-common/lib/testcontainers/index.js";
 
 const DEFAULT_CONFIG = {
     version: 2,
diff --git a/playwright/testcontainers/mas.ts b/playwright/testcontainers/mas.ts
index b8f37327bb..54941870ce 100644
--- a/playwright/testcontainers/mas.ts
+++ b/playwright/testcontainers/mas.ts
@@ -8,7 +8,7 @@ Please see LICENSE files in the repository root for full details.
 import {
     MatrixAuthenticationServiceContainer as BaseMatrixAuthenticationServiceContainer,
     type StartedPostgreSqlContainer,
-} from "@element-hq/element-web-playwright-common/lib/testcontainers";
+} from "@element-hq/element-web-playwright-common/lib/testcontainers/index.js";
 
 const TAG = "main@sha256:294e209b8e3c9dd0347e2baf01c34da9c6b0f27324ebccc5fbd6e221d08d16c3";
 
diff --git a/playwright/testcontainers/synapse.ts b/playwright/testcontainers/synapse.ts
index c68668761a..bc13c3582e 100644
--- a/playwright/testcontainers/synapse.ts
+++ b/playwright/testcontainers/synapse.ts
@@ -5,7 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Com
 Please see LICENSE files in the repository root for full details.
 */
 
-import { SynapseContainer as BaseSynapseContainer } from "@element-hq/element-web-playwright-common/lib/testcontainers";
+import { SynapseContainer as BaseSynapseContainer } from "@element-hq/element-web-playwright-common/lib/testcontainers/index.js";
 
 const TAG = "develop@sha256:f0de453dbb284112c4bc91be01345f189f218bf51ee09ed565dab295c0a72b44";
 
diff --git a/recorder-worklet-loader.js b/recorder-worklet-loader.cjs
similarity index 100%
rename from recorder-worklet-loader.js
rename to recorder-worklet-loader.cjs
diff --git a/sonar-project.properties b/sonar-project.properties
index c1d3f59842..26970ca7f4 100644
--- a/sonar-project.properties
+++ b/sonar-project.properties
@@ -7,7 +7,7 @@ sonar.organization=element-hq
 sonar.sources=src,res,packages/shared-components/src
 sonar.tests=test,playwright,src,packages
 sonar.test.inclusions=test/*,playwright/*,src/**/*.test.*,packages/*/src/**/*.test.*,packages/*/src/test/**/*
-sonar.exclusions=__mocks__,docs,element.io,nginx
+sonar.exclusions=__mocks__,docs,element.io,nginx,src/vector/modernizr.cjs
 
 sonar.cpd.exclusions=src/i18n/strings/*.json
 sonar.typescript.tsconfigPath=./tsconfig.json
@@ -17,7 +17,6 @@ sonar.coverage.exclusions=\
   playwright/**/*,\
   res/**/*,\
   scripts/**/*,\
-  src/vector/modernizr.js,\
   src/components/views/dialogs/devtools/**/*,\
   src/utils/SessionLock.ts,\
   src/**/*.d.ts,\
diff --git a/src/vector/index.ts b/src/vector/index.ts
index 3dfcbe6cdf..2010c95d75 100644
--- a/src/vector/index.ts
+++ b/src/vector/index.ts
@@ -15,7 +15,7 @@ import { shouldPolyfill as shouldPolyFillIntlSegmenter } from "@formatjs/intl-se
 
 // These are things that can run before the skin loads - be careful not to reference the react-sdk though.
 import { parseQsFromFragment } from "./url_utils";
-import "./modernizr";
+import "./modernizr.cjs";
 
 // Import shared components CSS
 import "@element-hq/web-shared-components/dist/element-web-shared-components.css";
diff --git a/src/vector/modernizr.js b/src/vector/modernizr.cjs
similarity index 99%
rename from src/vector/modernizr.js
rename to src/vector/modernizr.cjs
index 932513ebe8..87c3bca20e 100644
--- a/src/vector/modernizr.js
+++ b/src/vector/modernizr.cjs
@@ -1,5 +1,5 @@
 /*!
- * modernizr v3.13.0
+ * modernizr v3.13.1
  * Build https://modernizr.com/download?-cors-cryptography-cssanimations-cssfilters-displaytable-es5date-es5function-es5object-es5undefined-es6array-es6collections-es6string-fetch-flexbox-json-localstorage-objectfit-promises-resizeobserver-sandbox-svg-svgasimg-svgfilters-urlparser-urlsearchparams-webaudio-dontmin
  *
  * Copyright (c)
@@ -35,7 +35,7 @@
    * @access public
    */
   var ModernizrProto = {
-    _version: '3.13.0',
+    _version: '3.13.1',
 
     // Any settings that don't work as separate modules
     // can go in here as configuration.
diff --git a/webpack.config.js b/webpack.config.cjs
similarity index 99%
rename from webpack.config.js
rename to webpack.config.cjs
index 3ea0f68b0e..d2bccc5969 100644
--- a/webpack.config.js
+++ b/webpack.config.cjs
@@ -413,7 +413,7 @@ module.exports = (env, argv) => {
                     type: "javascript/auto",
                     use: [
                         {
-                            loader: path.resolve("./recorder-worklet-loader.js"),
+                            loader: path.resolve("./recorder-worklet-loader.cjs"),
                         },
                         {
                             loader: "babel-loader",
diff --git a/yarn.lock b/yarn.lock
index 11df90f1a3..d80bb14424 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -9621,6 +9621,11 @@ lodash@^4.17.15, lodash@^4.17.20, lodash@^4.17.21:
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.23.tgz#f113b0378386103be4f6893388c73d0bde7f2c5a"
   integrity sha512-LgVTMpQtIopCi79SJeDiP0TfWi5CNEc/L/aRdTh3yIvmZXTnheWpKjSZhnvMl8iXbC1tFg9gdHHDMLoV7CnG+w==
 
+"lodash@npm:lodash-es@^4.17.21":
+  version "4.17.23"
+  resolved "https://registry.yarnpkg.com/lodash-es/-/lodash-es-4.17.23.tgz#58c4360fd1b5d33afc6c0bbd3d1149349b1138e0"
+  integrity sha512-kVI48u3PZr38HdYz98UmfPnXl2DXrpdctLrFLCd3kOx1xUkOmpFPx7gCWWM5MPkL/fD8zb+Ph0QzjGFs4+hHWg==
+
 log-update@^6.1.0:
   version "6.1.0"
   resolved "https://registry.yarnpkg.com/log-update/-/log-update-6.1.0.tgz#1a04ff38166f94647ae1af562f4bd6a15b1b7cd4"