--- a/toolkit/content/widgets/autocomplete.xml
+++ b/toolkit/content/widgets/autocomplete.xml
@@ -1245,16 +1245,19 @@ extends="chrome://global/content/binding
             if (numRows > this.maxRows) {
               // Set a fixed max-height to avoid flicker when growing the panel.
               let lastVisibleRowRect = rows[this.maxRows - 1].getBoundingClientRect();
               let visibleHeight = lastVisibleRowRect.bottom - firstRowRect.top;
               this.richlistbox.style.maxHeight =
                 visibleHeight + this._rlbPadding + "px";
             }
 
+            for (let i = 0; i < numRows; i++) {
+              rows[i]._handleOverflow();
+            }
             let lastRowRect = rows[numRows - 1].getBoundingClientRect();
             // Calculate the height to have the first row to last row shown
             height = lastRowRect.bottom - firstRowRect.top +
                      this._rlbPadding;
           }
 
           let animate = this._rlbAnimated &&
                         this.getAttribute("dontanimate") != "true";