diff --git a/Perspex.Application/Application.cs b/Perspex.Application/Application.cs
index 634b7f88c3..4bd43a5984 100644
--- a/Perspex.Application/Application.cs
+++ b/Perspex.Application/Application.cs
@@ -42,8 +42,6 @@ namespace Perspex
         /// </summary>
         private Styler styler = new Styler();
 
-        private ICloseable mainWindow;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="Application"/> class.
         /// </summary>