diff --git a/js/src/tooltip.js b/js/src/tooltip.js
index 5cf56ce6e39af84ed165dd663b59d7c822f2fd7b..db626048f67bf56f91080b7b9157c09204f08643 100644
--- a/js/src/tooltip.js
+++ b/js/src/tooltip.js
@@ -199,9 +199,7 @@ class Tooltip extends BaseComponent {
 
     const showEvent = EventHandler.trigger(this._element, this.constructor.eventName(EVENT_SHOW))
     const shadowRoot = findShadowRoot(this._element)
-    const isInTheDom = shadowRoot === null ?
-      this._element.ownerDocument.documentElement.contains(this._element) :
-      shadowRoot.contains(this._element)
+    const isInTheDom = (shadowRoot || this._element.ownerDocument.documentElement).contains(this._element)
 
     if (showEvent.defaultPrevented || !isInTheDom) {
       return