diff --git a/package-lock.json b/package-lock.json
index d5a00294..835de852 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -38,6 +38,7 @@
         "@vue/test-utils": "^1.3.6",
         "@vue/tsconfig": "^0.5.1",
         "@zamiell/typedoc-plugin-not-exported": "^0.3.0",
+        "core-js": "^3.39.0",
         "gettext-extractor": "^3.8.0",
         "gettext-parser": "^8.0.0",
         "happy-dom": "^14.12.3",
@@ -1444,6 +1445,17 @@
         "npm": "^9.0.0"
       }
     },
+    "node_modules/@nextcloud/browser-storage/node_modules/core-js": {
+      "version": "3.33.0",
+      "resolved": "https://registry.npmjs.org/core-js/-/core-js-3.33.0.tgz",
+      "integrity": "sha512-HoZr92+ZjFEKar5HS6MC776gYslNOKHt75mEBKWKnPeFDpZ6nH5OeF3S6HFT1mUAUZKrzkez05VboaX8myjSuw==",
+      "hasInstallScript": true,
+      "peer": true,
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/core-js"
+      }
+    },
     "node_modules/@nextcloud/browserslist-config": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/@nextcloud/browserslist-config/-/browserslist-config-3.0.1.tgz",
@@ -4344,11 +4356,10 @@
       }
     },
     "node_modules/core-js": {
-      "version": "3.33.0",
-      "resolved": "https://registry.npmjs.org/core-js/-/core-js-3.33.0.tgz",
-      "integrity": "sha512-HoZr92+ZjFEKar5HS6MC776gYslNOKHt75mEBKWKnPeFDpZ6nH5OeF3S6HFT1mUAUZKrzkez05VboaX8myjSuw==",
+      "version": "3.39.0",
+      "resolved": "https://registry.npmjs.org/core-js/-/core-js-3.39.0.tgz",
+      "integrity": "sha512-raM0ew0/jJUqkJ0E6e8UDtl+y/7ktFivgWvqw8dNSQeNWoSDLvQ1H/RN3aPXB9tBd4/FhyR4RDPGhsNIMsAn7g==",
       "hasInstallScript": true,
-      "peer": true,
       "funding": {
         "type": "opencollective",
         "url": "https://opencollective.com/core-js"
diff --git a/package.json b/package.json
index b658f18c..a64a6801 100644
--- a/package.json
+++ b/package.json
@@ -83,6 +83,7 @@
     "@vue/test-utils": "^1.3.6",
     "@vue/tsconfig": "^0.5.1",
     "@zamiell/typedoc-plugin-not-exported": "^0.3.0",
+    "core-js": "^3.39.0",
     "gettext-extractor": "^3.8.0",
     "gettext-parser": "^8.0.0",
     "happy-dom": "^14.12.3",
diff --git a/test/setup.ts b/test/setup.ts
new file mode 100644
index 00000000..c731e24c
--- /dev/null
+++ b/test/setup.ts
@@ -0,0 +1,7 @@
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: CC0-1.0
+ */
+
+// Polyfill like the server does
+import 'core-js/stable/index.js'
diff --git a/vite.config.ts b/vite.config.ts
index b54a55b1..70db91b6 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -31,29 +31,6 @@ export default defineConfig((env) => {
 				// Fix for vite config, TODO: remove with next release
 				cssCodeSplit: false,
 			},
-			// vitest configuration
-			test: {
-				environment: 'happy-dom',
-				coverage: {
-					all: true,
-					provider: 'v8',
-					include: ['lib/**/*.ts', 'lib/*.ts'],
-					exclude: ['lib/**/*.spec.ts'],
-				},
-				css: {
-					modules: {
-						classNameStrategy: 'non-scoped',
-					},
-				},
-				server: {
-					deps: {
-						inline: [
-							/@nextcloud\/vue/, // Fix unresolvable .css extension for ssr
-							/@nextcloud\/files/, // Fix CommonJS cancelable-promise not supporting named exports
-						],
-					},
-				},
-			},
 		},
 		// We build for ESM and legacy common js
 		libraryFormats: ['es', 'cjs'],
diff --git a/vitest.config.ts b/vitest.config.ts
index 4616f23b..702ca11e 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -3,11 +3,41 @@
  * SPDX-License-Identifier: CC0-1.0
  */
 import type { ConfigEnv } from 'vite'
+import { defineConfig, type ViteUserConfig } from 'vitest/config'
 import config from './vite.config'
 
-export default async (env: ConfigEnv) => {
+export default defineConfig(async (env: ConfigEnv): Promise<ViteUserConfig> => {
 	const cfg = await config(env)
-	// filter node-externals which will interfere with vitest
-	cfg.plugins = cfg.plugins!.filter((plugin) => plugin && (!('name' in plugin) || plugin.name !== 'node-externals'))
-	return cfg
-}
+
+	return {
+		...cfg,
+
+		// filter node-externals which will interfere with vitest
+		plugins: cfg.plugins!.filter((plugin) => plugin && (!('name' in plugin) || plugin.name !== 'node-externals')),
+
+		// vitest configuration
+		test: {
+			environment: 'happy-dom',
+			coverage: {
+				all: true,
+				provider: 'v8',
+				include: ['lib/**/*.ts', 'lib/*.ts'],
+				exclude: ['lib/**/*.spec.ts'],
+			},
+			css: {
+				modules: {
+					classNameStrategy: 'non-scoped',
+				},
+			},
+			setupFiles: 'test/setup.ts',
+			server: {
+				deps: {
+					inline: [
+						/@nextcloud\/vue/, // Fix unresolvable .css extension for ssr
+						/@nextcloud\/files/, // Fix CommonJS cancelable-promise not supporting named exports
+					],
+				},
+			},
+		},
+	}
+})