diff --git a/js/ui/workspace.js b/js/ui/workspace.js
index 354a2608f..693414812 100644
--- a/js/ui/workspace.js
+++ b/js/ui/workspace.js
@@ -217,7 +217,7 @@ var WindowPreview = GObject.registerClass({
     _init(metaWindow, workspace) {
         this.metaWindow = metaWindow;
         this.metaWindow._delegate = this;
-        this.realWindow = metaWindow.get_compositor_private();
+        this._windowActor = metaWindow.get_compositor_private();
         this._workspace = workspace;
 
         super._init({
@@ -235,7 +235,7 @@ var WindowPreview = GObject.registerClass({
         this._windowContainer.layout_manager = new WindowPreviewLayout();
         this.add_child(this._windowContainer);
 
-        this._addWindow(realWindow.meta_window);
+        this._addWindow(metaWindow);
 
         this._delegate = this;
 
@@ -250,7 +250,7 @@ var WindowPreview = GObject.registerClass({
             });
 
         this._windowDestroyId =
-            this.realWindow.connect('destroy', () => this.destroy());
+            this._windowActor.connect('destroy', () => this.destroy());
 
         this._updateAttachedDialogs();
         this.x = this.boundingBox.x;
@@ -612,7 +612,7 @@ var WindowPreview = GObject.registerClass({
     }
 
     _onDestroy() {
-        this.realWindow.disconnect(this._windowDestroyId);
+        this._windowActor.disconnect(this._windowDestroyId);
 
         this.metaWindow._delegate = null;
         this._delegate = null;