diff --git a/test/shared/rwlock.test.ts b/test/shared/rwlock.test.ts
index 861c83f..b1e3b9b 100644
--- a/test/shared/rwlock.test.ts
+++ b/test/shared/rwlock.test.ts
@@ -119,16 +119,15 @@ describe('RwLock', () => {
     assert.deepEqual(results.sort(), ['r1', 'r2']);
   });
 
-  it('tryReadLock returns a guard when unlocked', () => {
+  it('tryReadLock returns a guard when unlocked', async () => {
     const rw = rwlock();
     const guard = rw.tryReadLock();
     assert.ok(guard);
     assert.equal(typeof guard[Symbol.dispose], 'function');
     guard[Symbol.dispose]();
-    // Should be able to read-lock again after dispose
-    const guard2 = rw.tryReadLock();
-    assert.ok(guard2);
-    rw.readUnlock();
+    // writeLock only succeeds if readUnlock was called (reader count back to 0)
+    await rw.writeLock();
+    rw.writeUnlock();
   });
 
   it('multiple concurrent tryReadLock calls all succeed', () => {