diff --git a/pom.xml b/pom.xml
index 99b88d4..f57ad38 100644
--- a/pom.xml
+++ b/pom.xml
@@ -24,7 +24,7 @@
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
-            <version>1.18.18</version>
+            <version>1.18.22</version>
         </dependency>
 
         <dependency>
diff --git a/src/main/java/de/dj_steam/bot/domain/Command.java b/src/main/java/de/dj_steam/bot/domain/Command.java
index 1da4b86..6f7e439 100644
--- a/src/main/java/de/dj_steam/bot/domain/Command.java
+++ b/src/main/java/de/dj_steam/bot/domain/Command.java
@@ -10,10 +10,10 @@ import lombok.Getter;
  * @author steam
  *
  * this is a general command implementation.
- *
+ * <p>
  * The arguments as {@link String} is intentionally, to be flexible
  * define some different argument formats.
- *
+ * <p>
  * Use some kind of {@link List} for arguments in futher implementations.
  */
 
@@ -27,9 +27,9 @@ public class Command {
     public static final String PLACE = "PLACE";
     public static final String REPORT = "REPORT";
 
-    private String command;
+    private final String command;
 
-    private Optional<String> arguments;
+    private final Optional<String> arguments;
 
     public Command(final String command, Optional<String> arguments) {
         this.command = command;
diff --git a/src/main/java/de/dj_steam/bot/domain/Position.java b/src/main/java/de/dj_steam/bot/domain/Position.java
index 7567023..e80e326 100644
--- a/src/main/java/de/dj_steam/bot/domain/Position.java
+++ b/src/main/java/de/dj_steam/bot/domain/Position.java
@@ -14,8 +14,8 @@ import lombok.ToString;
 @ToString
 @EqualsAndHashCode
 public class Position {
-    private int x;
-    private int y;
+    private final int x;
+    private final int y;
 
     public Position() {
         this.x = 0;
diff --git a/src/main/java/de/dj_steam/bot/domain/ToyBotField.java b/src/main/java/de/dj_steam/bot/domain/ToyBotField.java
index b6b6125..2fb5980 100644
--- a/src/main/java/de/dj_steam/bot/domain/ToyBotField.java
+++ b/src/main/java/de/dj_steam/bot/domain/ToyBotField.java
@@ -11,8 +11,8 @@ import lombok.Getter;
 
 @Getter
 public class ToyBotField {
-    private int width = 4;
-    private int height = 4;
+    private final int width = 4;
+    private final int height = 4;
 
     public boolean isInsideTheField(final Position position) {
         return (position.getX() >= 0 &&
diff --git a/src/main/java/de/dj_steam/bot/moving/DirectionCalculator.java b/src/main/java/de/dj_steam/bot/moving/DirectionCalculator.java
index 5128f08..0b1fd24 100644
--- a/src/main/java/de/dj_steam/bot/moving/DirectionCalculator.java
+++ b/src/main/java/de/dj_steam/bot/moving/DirectionCalculator.java
@@ -13,7 +13,7 @@ import de.dj_steam.bot.domain.ToyBot;
  */
 public class DirectionCalculator {
 
-    private LoopedDirectionsArrayList<Direction> directions;
+    private final LoopedDirectionsArrayList<Direction> directions;
 
     public DirectionCalculator() {
         directions = new LoopedDirectionsArrayList();
diff --git a/src/main/java/de/dj_steam/bot/moving/strategy/TurnStrategy.java b/src/main/java/de/dj_steam/bot/moving/strategy/TurnStrategy.java
index c795429..38f6925 100644
--- a/src/main/java/de/dj_steam/bot/moving/strategy/TurnStrategy.java
+++ b/src/main/java/de/dj_steam/bot/moving/strategy/TurnStrategy.java
@@ -12,7 +12,7 @@ import de.dj_steam.bot.moving.DirectionCalculator;
  */
 public class TurnStrategy implements ChangingStrategy {
 
-    private DirectionCalculator directionCalculator;
+    private final DirectionCalculator directionCalculator;
 
     public TurnStrategy() {
         directionCalculator = new DirectionCalculator();
diff --git a/src/test/java/de/dj_steam/bot/cli/LoopingConsoleTest.java b/src/test/java/de/dj_steam/bot/cli/LoopingConsoleTest.java
index dcb3914..f45618e 100644
--- a/src/test/java/de/dj_steam/bot/cli/LoopingConsoleTest.java
+++ b/src/test/java/de/dj_steam/bot/cli/LoopingConsoleTest.java
@@ -15,12 +15,12 @@ public class LoopingConsoleTest {
 
 
     @Test(expected = InvalidUserInputException.class)
-    public void createCommandExpectedUserInputExceptionOnEmptyInput() throws Exception {
+    public void createCommandExpectedUserInputExceptionOnEmptyInput() {
         LoopingConsole.createCommand("");
     }
 
     @Test(expected = InvalidUserInputException.class)
-    public void createCommandExpectedUserInputExceptionOnMoreThenTwoParams() throws Exception {
+    public void createCommandExpectedUserInputExceptionOnMoreThenTwoParams() {
         LoopingConsole.createCommand("INPUT X,Y,F WRONG_PARAM");
     }
 
diff --git a/src/test/java/de/dj_steam/bot/domain/ToyBotFieldTest.java b/src/test/java/de/dj_steam/bot/domain/ToyBotFieldTest.java
index e2c9b41..2764099 100644
--- a/src/test/java/de/dj_steam/bot/domain/ToyBotFieldTest.java
+++ b/src/test/java/de/dj_steam/bot/domain/ToyBotFieldTest.java
@@ -10,7 +10,7 @@ import org.junit.Test;
  */
 public class ToyBotFieldTest {
     @Test
-    public void isInsideTheField() throws Exception {
+    public void isInsideTheField() {
         ToyBotField toyBotField = new ToyBotField();
         assertTrue(toyBotField.isInsideTheField(new Position(0,0)));
         assertTrue(toyBotField.isInsideTheField(new Position(4,4)));
diff --git a/src/test/java/de/dj_steam/bot/engine/ToyBotEngineTest.java b/src/test/java/de/dj_steam/bot/engine/ToyBotEngineTest.java
index 803e5c7..90a2ce7 100644
--- a/src/test/java/de/dj_steam/bot/engine/ToyBotEngineTest.java
+++ b/src/test/java/de/dj_steam/bot/engine/ToyBotEngineTest.java
@@ -26,7 +26,7 @@ public class ToyBotEngineTest {
     private Command moveCommand;
     private Command placeCommand;
 
-    private ToyBotField toyBotField = new ToyBotField();
+    private final ToyBotField toyBotField = new ToyBotField();
 
     @Before
     public void setup() {