diff --git a/src/main/java/app/CarControlBoard.java b/src/main/java/app/CarControlBoard.java
index dd62d7c..df74cbc 100644
--- a/src/main/java/app/CarControlBoard.java
+++ b/src/main/java/app/CarControlBoard.java
@@ -35,7 +35,7 @@
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
-public class CarControlBoard extends Application {
+public final class CarControlBoard extends Application {
 
     public static final ExecutorService EXECUTOR_SERVICE = Executors.newCachedThreadPool();
 
diff --git a/src/main/java/controllers/GmapfxController.java b/src/main/java/controllers/GmapfxController.java
index 3df4215..cdd4a53 100644
--- a/src/main/java/controllers/GmapfxController.java
+++ b/src/main/java/controllers/GmapfxController.java
@@ -50,7 +50,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class GmapfxController implements MapComponentInitializedListener, DirectionsServiceCallback, GeocodingServiceCallback {
+public final class GmapfxController implements MapComponentInitializedListener, DirectionsServiceCallback, GeocodingServiceCallback {
 
     private final static Logger LOGGER = LoggerFactory.getLogger(GmapfxController.class);
 
diff --git a/src/main/java/controllers/MainController.java b/src/main/java/controllers/MainController.java
index c352444..f22c0ea 100644
--- a/src/main/java/controllers/MainController.java
+++ b/src/main/java/controllers/MainController.java
@@ -39,7 +39,7 @@
 import javafx.scene.layout.VBox;
 import javafx.stage.Stage;
 
-public class MainController {
+public final class MainController {
 
     private final Stage primaryStage;