diff --git a/vitest.integration.config.ts b/vitest.integration.config.ts
index 2f38feb..3bb0292 100644
--- a/vitest.integration.config.ts
+++ b/vitest.integration.config.ts
@@ -20,5 +20,10 @@ export default defineConfig({
     environment: "node",
     include: ["src/__tests__/integration/**/*.test.ts"],
     pool: "forks",
+    // Every integration file shares the one `personal_test` database, and
+    // helpers.resetDB() TRUNCATEs it (CASCADE reaches expense_metadata).
+    // Run files one at a time so a sibling's reset cannot delete rows another
+    // file just inserted — that raced non-deterministically across I6/I7/I11.
+    fileParallelism: false,
   },
 });