diff --git a/bunfig.toml b/bunfig.toml
index e5171ab..fadb68d 100644
--- a/bunfig.toml
+++ b/bunfig.toml
@@ -1,3 +1,4 @@
 [test]
 root = "tests/"
 timeout = 30_000
+preload = ["./tests/setup.ts"]
diff --git a/tests/helpers/db.ts b/tests/helpers/db.ts
index 6a181de..4a3ca02 100644
--- a/tests/helpers/db.ts
+++ b/tests/helpers/db.ts
@@ -7,7 +7,7 @@ import * as schema from "../../src/db/schema.ts";
 type Db = ReturnType<typeof drizzle<typeof schema>>;
 
 // Cache: one PGlite instance per test file (per worker)
-let cachedClient: PGlite | null = null;
+export let cachedClient: PGlite | null = null;
 let cachedDb: Db | null = null;
 
 async function getOrCreateDb(): Promise<Db> {
diff --git a/tests/setup.ts b/tests/setup.ts
new file mode 100644
index 0000000..04283bb
--- /dev/null
+++ b/tests/setup.ts
@@ -0,0 +1,9 @@
+// Bun test preload: close PGlite WASM worker after each file to prevent exit code 100 (leaked handles).
+import { afterAll } from "bun:test";
+import { cachedClient } from "./helpers/db.ts";
+
+afterAll(async () => {
+	if (cachedClient) {
+		await cachedClient.close();
+	}
+});