--- a/testing/marionette/element.js
+++ b/testing/marionette/element.js
@@ -918,21 +918,16 @@ element.isVisible = function (el, x = un
     element.scrollIntoView(el);
     if (!element.inViewport(el)) {
       return false;
     }
   }
   return true;
 };
 
-element.isInteractable = function (el) {
-  return element.isPointerInteractable(el) ||
-      element.isKeyboardInteractable(el);
-};
-
 /**
  * A pointer-interactable element is defined to be the first
  * non-transparent element, defined by the paint order found at the centre
  * point of its rectangle that is inside the viewport, excluding the size
  * of any rendered scrollbars.
  *
  * @param {DOMElement} el
  *     Element determine if is pointer-interactable.