diff --git a/src/elements/play-assets/play-assets.test.ts b/src/elements/play-assets/play-assets.test.ts
new file mode 100644
index 0000000..4a42844
--- /dev/null
+++ b/src/elements/play-assets/play-assets.test.ts
@@ -0,0 +1,7 @@
+import {assert} from '@esm-bundle/chai'
+import {PlayAssets} from './play-assets'
+
+test('tag is defined', () => {
+  const el = document.createElement('play-assets')
+  assert.instanceOf(el, PlayAssets)
+})
diff --git a/src/elements/play-assets/play-assets.ts b/src/elements/play-assets/play-assets.ts
index 79591bd..e2403c3 100644
--- a/src/elements/play-assets/play-assets.ts
+++ b/src/elements/play-assets/play-assets.ts
@@ -1,6 +1,5 @@
 import {type PropertyValues, ReactiveElement} from 'lit'
 import {customElement, property} from 'lit/decorators.js'
-import {PlayPen} from '../play-pen/play-pen.js'
 import {WebAccess, WebStorage} from '@zenfs/dom'
 import {Bubble} from '../../utils/bubble.js'
 import {Zip} from '@zenfs/zip'
@@ -38,7 +37,7 @@ const DEFAULT_MIME = 'application/octet-stream'
 
 declare global {
   interface HTMLElementTagNameMap {
-    'play-pen': PlayPen
+    'play-assets': PlayAssets
   }
   interface HTMLElementEventMap {
     'assets-updated': CustomEvent<void>