diff --git a/services/auth/vitest.config.ts b/services/auth/vitest.config.ts
index 2c76e30..2075bce 100644
--- a/services/auth/vitest.config.ts
+++ b/services/auth/vitest.config.ts
@@ -2,6 +2,10 @@ import { defineConfig } from "vitest/config";
 
 export default defineConfig({
   test: {
+    // Real Argon2id hashes cost 1-3s each on a shared CI runner, and several
+    // tests chain a dozen of them. The production cost parameters stay as they
+    // are; the default 5s budget is what does not fit.
+    testTimeout: 30_000,
     // session.ts refuses to load without a real signing secret, and ESM hoists
     // imports - so the value has to exist before any test file is evaluated,
     // which an assignment inside a test file cannot guarantee.