diff --git a/tests/js/qrcode.test.js b/tests/js/qrcode.test.js
index 7767620e..2802b070 100644
--- a/tests/js/qrcode.test.js
+++ b/tests/js/qrcode.test.js
@@ -1,5 +1,5 @@
 import 'qrcode/qrcode-reader.js'
-import { expect, test, vi} from 'vitest'
+import { expect, test, vi } from 'vitest'
 import ZXingBrowser from 'qrcode/zxing-browser.min.js'
 import nacl from 'qrcode/nacl.min.js'
 
@@ -26,7 +26,6 @@ const certificateWithoutValidity =
   'B3X3PP0TH9CN2R3IYEDB$DKWEOED0%EIEC ED3.DQ34%R83:6NW6XM8ME1.$E8UCE44QIC+96M.C9%6I' +
   'M6E467W5LA76L6%47G%64W5ZJCYX6J*64EC6:6J$6'
 
-
 const qrcodeReaderTest = test.extend({
   mock: async ({ task }, use) => {
     let resolveResult = undefined
@@ -66,6 +65,7 @@ const qrcodeReaderTest = test.extend({
     const fetchBackup = global.fetch
     global.fetch = vi.fn()
 
+    vi.useFakeTimers({toFake: ['Date']})
     await use({
       reader,
       scan: async (text) => {
@@ -74,14 +74,12 @@ const qrcodeReaderTest = test.extend({
         await resultHandled
       }
     })
-    vi.useFakeTimers()
+    vi.useRealTimers()
 
     global.fetch = fetchBackup
 
     reader.remove()
 
-    vi.useRealTimers ()
-
     resolveResult(terminate)
     window.ZXingBrowser = savedZXingBrowser
     navigator.mediaDevices = undefined
@@ -112,7 +110,7 @@ qrcodeReaderTest('qrcode reader shows valid qrcode informations', async ({mock})
 
   const validity = popup.querySelector('.qrcode-reader--validity')
 
-  expect(validity.innerText).toMatch(/from :\s*31\/10\/2023 23:00:00\s*to :\s*01\/12\/2023 22:59:59/)
+  expect(validity.innerText).toMatch(/from :\s*10\/31\/2023, 11:00:00 PM\s*to :\s*12\/1\/2023, 10:59:59 PM/)
 
   const labels = popup.querySelectorAll('.qrcode-reader--data-item-label')
 
diff --git a/tox.ini b/tox.ini
index 0e96687a..c3a86f9c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -96,4 +96,5 @@ allowlist_externals =
 install_command = bash setup-vitest.sh {packages}
 setenv =
     NODE_PATH={envdir}/lib/node_modules
+    LC_ALL=en_US.UTF-8
 commands = npx vitest --run
diff --git a/vitest.config.js b/vitest.config.js
index 7f8f80ca..1be678c7 100644
--- a/vitest.config.js
+++ b/vitest.config.js
@@ -9,7 +9,10 @@ export default defineConfig({
       qrcode: fileURLToPath(new URL('./passerelle/apps/qrcode/static/qrcode/js', import.meta.url)),
       vitest: process.env.NODE_PATH + '/vitest'
     },
-    environment: 'happy-dom'
+    environment: 'happy-dom',
+    chaiConfig: {
+      truncateThreshold: Infinity,
+    },
   }
 })