diff --git a/src/Backend.cs b/src/Backend.cs
index aa443e9..b302473 100644
--- a/src/Backend.cs
+++ b/src/Backend.cs
@@ -110,5 +110,12 @@ namespace WorldOfPeacecraft
 		{
 			Gui.PerformRefresh();
 		}
+
+		public void Stop() {
+			Parse.Stop ();
+			Send.Stop ();
+			Rec.Stop ();
+			System.Windows.Forms.Application.Exit ();
+		}
 	}
 }
diff --git a/src/Gui/Gui.cs b/src/Gui/Gui.cs
index 8adfd09..6121d8f 100644
--- a/src/Gui/Gui.cs
+++ b/src/Gui/Gui.cs
@@ -42,6 +42,12 @@ namespace WorldOfPeacecraft
             this.PerformLayout();
 		}
 
+		protected override void OnClosing (System.ComponentModel.CancelEventArgs e)
+		{
+			base.OnClosing (e);
+			Backend.Stop ();
+		}
+
 		public void DoPaint (object source, PaintEventArgs args)
 		{
 			BufferedGraphics buffer = BufferedGraphicsManager.Current.Allocate (Board.CreateGraphics (), Board.DisplayRectangle);
diff --git a/src/Gui/IBackend.cs b/src/Gui/IBackend.cs
index 1ec4fc5..85fe8cb 100644
--- a/src/Gui/IBackend.cs
+++ b/src/Gui/IBackend.cs
@@ -4,5 +4,7 @@ namespace WorldOfPeacecraft
 	public interface IBackend
 	{
 		ITile[,] GetMap();
+
+		void Stop();
 	}
 }
diff --git a/src/Sender.cs b/src/Sender.cs
index 93b1ce0..72252e4 100644
--- a/src/Sender.cs
+++ b/src/Sender.cs
@@ -34,7 +34,7 @@ namespace WorldOfPeacecraft
 			}
 		}
 
-		public void stop()
+		public void Stop()
 		{
 			SenderThread.Abort();
 		}