diff --git a/RhSolutions.AddIn/Controllers/RibbonController.cs b/RhSolutions.AddIn/Controllers/RibbonController.cs
index b33f6d6..aecdc02 100644
--- a/RhSolutions.AddIn/Controllers/RibbonController.cs
+++ b/RhSolutions.AddIn/Controllers/RibbonController.cs
@@ -2,6 +2,7 @@
 using System.IO;
 using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Windows.Forms;
 
 namespace RhSolutions.Controllers;