diff --git a/ProjectAirFighter/ProjectAirFighter/FormWarPlaneConfig.cs b/ProjectAirFighter/ProjectAirFighter/FormWarPlaneConfig.cs
index 71fc646..ae3c00f 100644
--- a/ProjectAirFighter/ProjectAirFighter/FormWarPlaneConfig.cs
+++ b/ProjectAirFighter/ProjectAirFighter/FormWarPlaneConfig.cs
@@ -156,10 +156,12 @@ public partial class FormWarPlaneConfig : Form
     }
     private void labelAdditionalColor_DragEnter(object sender, DragEventArgs e)
     {
-        if (e.Data.GetDataPresent(typeof(Color)))
+        if (_warPlane?.EntityWarPlane is EntityAirFighter _airFighter) { 
+            if (e.Data.GetDataPresent(typeof(Color)))
             e.Effect = DragDropEffects.Copy;
         else
             e.Effect = DragDropEffects.None;
+        }
     }
 
     private void buttonAdd_Click(object sender, EventArgs e)