--- a/toolkit/modules/FinderHighlighter.jsm
+++ b/toolkit/modules/FinderHighlighter.jsm
@@ -564,17 +564,17 @@ FinderHighlighter.prototype = {
    *                                        Optional, defaults to `true`
    * @return {Rect}
    */
   _getRootBounds(window, includeScroll = true) {
     let dwu = this._getDWU(window.top);
     let cssPageRect = Rect.fromRect(dwu.getRootBounds());
     let scrollX = {};
     let scrollY = {};
-    if (includeScroll) {
+    if (includeScroll && window == window.top) {
       dwu.getScrollXY(false, scrollX, scrollY);
       cssPageRect.translate(scrollX.value, scrollY.value);
     }
 
     // If we're in a frame, update the position of the rect (top/ left).
     let currWin = window;
     while (currWin != window.top) {
       // Since the frame is an element inside a parent window, we'd like to