diff --git a/src/dev/kske/chess/Board.java b/src/dev/kske/chess/Board.java
index 9fa33b9..ab431ee 100644
--- a/src/dev/kske/chess/Board.java
+++ b/src/dev/kske/chess/Board.java
@@ -128,7 +128,9 @@ public class Board {
 				if (get(pos) != null && get(pos).getColor() != color
 						&& get(pos).isValidMove(new Move(pos, kingPos.get(color))))
 					return GameEventType.CHECK;
-					//return getMoves(kingPos.get(color)).isEmpty() ? GameEventType.CHECKMATE : GameEventType.CHECK;
+				// TOOD: Checkmate detection
+				// return getMoves(kingPos.get(color)).isEmpty() ? GameEventType.CHECKMATE :
+				// GameEventType.CHECK;
 			}
 		return GameEventType.NONE;
 	}
diff --git a/src/dev/kske/chess/BoardPanel.java b/src/dev/kske/chess/ui/BoardPanel.java
similarity index 93%
rename from src/dev/kske/chess/BoardPanel.java
rename to src/dev/kske/chess/ui/BoardPanel.java
index d61e08a..3210635 100644
--- a/src/dev/kske/chess/BoardPanel.java
+++ b/src/dev/kske/chess/ui/BoardPanel.java
@@ -1,4 +1,4 @@
-package dev.kske.chess;
+package dev.kske.chess.ui;
 
 import java.awt.Color;
 import java.awt.Dimension;
@@ -13,6 +13,9 @@ import java.util.List;
 import javax.swing.JOptionPane;
 import javax.swing.JPanel;
 
+import dev.kske.chess.Board;
+import dev.kske.chess.Move;
+import dev.kske.chess.Position;
 import dev.kske.chess.event.GameEvent;
 import dev.kske.chess.event.GameEventListener;
 
diff --git a/src/dev/kske/chess/Chess.java b/src/dev/kske/chess/ui/MainWindow.java
similarity index 82%
rename from src/dev/kske/chess/Chess.java
rename to src/dev/kske/chess/ui/MainWindow.java
index 58be468..cb1c20b 100644
--- a/src/dev/kske/chess/Chess.java
+++ b/src/dev/kske/chess/ui/MainWindow.java
@@ -1,4 +1,4 @@
-package dev.kske.chess;
+package dev.kske.chess.ui;
 
 import java.awt.BorderLayout;
 import java.awt.EventQueue;
@@ -7,14 +7,16 @@ import javax.swing.JButton;
 import javax.swing.JFrame;
 import javax.swing.JPanel;
 
+import dev.kske.chess.Board;
+
 
 /**
  * Project: <strong>Chess</strong><br>
- * File: <strong>Chess.java</strong><br>
+ * File: <strong>MainWindow.java</strong><br>
  * Created: <strong>01.07.2019</strong><br>
  * Author: <strong>Kai S. K. Engelbart</strong>
  */
-public class Chess {
+public class MainWindow {
 
 	private JFrame mframe;
 
@@ -26,7 +28,7 @@ public class Chess {
 
 			public void run() {
 				try {
-					Chess window = new Chess();
+					MainWindow window = new MainWindow();
 					window.mframe.setVisible(true);
 				} catch (Exception e) {
 					e.printStackTrace();
@@ -38,7 +40,7 @@ public class Chess {
 	/**
 	 * Create the application.
 	 */
-	public Chess() {
+	public MainWindow() {
 		initialize();
 	}
 
diff --git a/src/dev/kske/chess/TextureUtil.java b/src/dev/kske/chess/ui/TextureUtil.java
similarity index 94%
rename from src/dev/kske/chess/TextureUtil.java
rename to src/dev/kske/chess/ui/TextureUtil.java
index cd336f8..b7267ce 100644
--- a/src/dev/kske/chess/TextureUtil.java
+++ b/src/dev/kske/chess/ui/TextureUtil.java
@@ -1,4 +1,4 @@
-package dev.kske.chess;
+package dev.kske.chess.ui;
 
 import java.awt.Image;
 import java.awt.image.BufferedImage;