diff --git a/Tests/ComposableArchitectureTests/UIKit/DiffableDataSourceQueueTests.swift b/Tests/ComposableArchitectureTests/UIKit/DiffableDataSourceQueueTests.swift
new file mode 100644
index 000000000000..dbac0a254b86
--- /dev/null
+++ b/Tests/ComposableArchitectureTests/UIKit/DiffableDataSourceQueueTests.swift
@@ -0,0 +1,40 @@
+#if canImport(UIKit) && !os(watchOS)
+import Dispatch
+import UIKit
+import XCTest
+
+@testable import ComposableArchitecture
+
+class CollectionView: UICollectionView {
+  override func reloadData() {
+    super.reloadData()
+    mainActorNow {
+      XCTAssertTrue(Thread.isMainThread)
+    }
+  }
+}
+
+@available(iOS 13.0, *)
+final class DiffableDataSourceQueueTests: BaseTCATestCase {
+  @MainActor
+  func testDiffableDataSourceWithMainActorNow() async {
+    let collectionView = CollectionView(
+      frame: .init(x: 0, y: 0, width: 10, height: 10),
+      collectionViewLayout: UICollectionViewFlowLayout()
+    )
+    collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
+
+    let dataSource = UICollectionViewDiffableDataSource<Int, Int>(
+      collectionView: collectionView
+    ) { collectionView, indexPath, item in
+      collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
+    }
+
+    var snapshot = NSDiffableDataSourceSnapshot<Int, Int>()
+    snapshot.appendSections([0])
+    snapshot.appendItems([1])
+    dataSource.apply(snapshot, animatingDifferences: true)
+  }
+}
+
+#endif