--- a/toolkit/modules/SelectParentHelper.jsm
+++ b/toolkit/modules/SelectParentHelper.jsm
@@ -3,16 +3,19 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 this.EXPORTED_SYMBOLS = [
   "SelectParentHelper"
 ];
 
+const {utils: Cu} = Components;
+const {AppConstants} = Cu.import("resource://gre/modules/AppConstants.jsm");
+
 // Maximum number of rows to display in the select dropdown.
 const MAX_ROWS = 20;
 
 // Interval between autoscrolls
 const AUTOSCROLL_INTERVAL = 25;
 
 var currentBrowser = null;
 var currentMenulist = null;
@@ -58,17 +61,17 @@ this.SelectParentHelper = {
 
     menupopup.classList.toggle("isOpenedViaTouch", isOpenedViaTouch);
 
     let constraintRect = browser.getBoundingClientRect();
     constraintRect = new win.DOMRect(constraintRect.left + win.mozInnerScreenX,
                                      constraintRect.top + win.mozInnerScreenY,
                                      constraintRect.width, constraintRect.height);
     menupopup.setConstraintRect(constraintRect);
-    menupopup.openPopupAtScreenRect("after_start", rect.left, rect.top, rect.width, rect.height, false, false);
+    menupopup.openPopupAtScreenRect(AppConstants.platform == "macosx" ? "selection" : "after_start", rect.left, rect.top, rect.width, rect.height, false, false);
 
     // Set up for dragging
     menupopup.setCaptureAlways();
     this.draggedOverPopup = false;
     menupopup.addEventListener("mousemove", this);
   },
 
   hide: function(menulist, browser) {