diff --git a/playground/vitestSetup.ts b/playground/vitestSetup.ts
index 70ac682d..13e7592a 100644
--- a/playground/vitestSetup.ts
+++ b/playground/vitestSetup.ts
@@ -182,7 +182,9 @@ export async function startDefaultServe() {
     build: {
       // esbuild do not minify ES lib output since that would remove pure annotations and break tree-shaking
       // skip transpilation during tests to make it faster
-      target: 'esnext'
+      target: 'esnext',
+      // tests are flaky when `emptyOutDir` is `true`
+      emptyOutDir: false
     },
     customLogger: createInMemoryLogger(serverLogs)
   }