diff --git a/tp-tree-nav.js b/tp-tree-nav.js
index e23f0a4..63c0f7e 100644
--- a/tp-tree-nav.js
+++ b/tp-tree-nav.js
@@ -151,9 +151,10 @@ export class TpTreeNav extends Position(LitElement) {
     }
 
     return html`
-      <div class="tree">
+      <div class="tree" part="tree">
         ${virtualize({
           items,
+          scroller: this,
           renderItem: (item) => this._renderItem(item),
           keyFunction: (item) => item.key,
         })}