diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index a78172047..be6a72190 100644
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -196,7 +196,7 @@ var ScreenShield = class {
         if (this._isModal)
             return true;
 
-        let grab = Main.pushModal(this.actor, { actionMode: Shell.ActionMode.LOCK_SCREEN });
+        let grab = Main.pushModal(Main.uiGroup, { actionMode: Shell.ActionMode.LOCK_SCREEN });
 
         // We expect at least a keyboard grab here
         this._isModal = (grab.get_seat_state() & Clutter.GrabState.KEYBOARD) !== 0;
diff --git a/js/ui/unlockDialog.js b/js/ui/unlockDialog.js
index bf81343b9..24c81609c 100644
--- a/js/ui/unlockDialog.js
+++ b/js/ui/unlockDialog.js
@@ -873,7 +873,7 @@ var UnlockDialog = GObject.registerClass({
             timestamp,
             actionMode: Shell.ActionMode.UNLOCK_SCREEN,
         };
-        let grab = Main.pushModal(this, modalParams);
+        let grab = Main.pushModal(Main.uiGroup, modalParams);
         if (grab.get_seat_state() !== Clutter.GrabState.ALL) {
             Main.popModal(grab);
             return false;