diff --git a/@MyGuiCont/MyGuiCont.m b/@MyGuiCont/MyGuiCont.m
index b433077..bc2cccb 100644
--- a/@MyGuiCont/MyGuiCont.m
+++ b/@MyGuiCont/MyGuiCont.m
@@ -1,25 +1,35 @@
 % Class that provides basic functionality for handling App-based GUIs
 
 classdef MyGuiCont < handle
     
     properties (Access = public)
         
-        % GUI object that is stored for reference only
+        % GUI object that is stored for reference only. Should include the
+        % main figure.
         Gui
         
         % Name of the GUI class that can be used with the instrument
         gui_name  char 
     end
     
     methods (Access = public)
         function createGui(this)
             assert(~isempty(this.gui_name), ['GUI name is not ' ...
                 'specified for the instrument class ' class(this)]);
             
             if isempty(this.Gui) || ~isvalid(this.Gui)
                 this.Gui = feval(this.gui_name, this);
             end
         end
     end
+    
+    methods
+        function set.Gui(this, Val)
+            assert(~isempty(findFigure(Val)), ...
+                'Value assigned to Gui property must include a figure');
+            
+            this.Gui = Val;
+        end
+    end
 end