diff --git a/.changeset/eager-islands-cheer.md b/.changeset/eager-islands-cheer.md
new file mode 100644
index 000000000000..8a674b039d49
--- /dev/null
+++ b/.changeset/eager-islands-cheer.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: avoid false-positive Vite config overridden warning when using Vitest 4
diff --git a/packages/kit/src/exports/vite/index.js b/packages/kit/src/exports/vite/index.js
index c1b12dbd06e6..68e5e90a4243 100644
--- a/packages/kit/src/exports/vite/index.js
+++ b/packages/kit/src/exports/vite/index.js
@@ -42,7 +42,7 @@ import { import_peer } from '../../utils/import.js';
 import { compact } from '../../utils/array.js';
 import { should_ignore } from './static_analysis/utils.js';
 
-const cwd = process.cwd();
+const cwd = posixify(process.cwd());
 
 /** @type {import('./types.js').EnforcedConfig} */
 const enforced_config = {