diff --git a/src/main/java/es/kauron/jstudy/controller/Controller.java b/src/main/java/es/kauron/jstudy/controller/Controller.java
index 0b117a3..0dd004d 100644
--- a/src/main/java/es/kauron/jstudy/controller/Controller.java
+++ b/src/main/java/es/kauron/jstudy/controller/Controller.java
@@ -91,7 +91,6 @@ public class Controller implements Initializable {
     private void checkUpdate() {
         // Check new version via gitlab's REST API
         String newVersion;
-        File jarFile;
         BufferedReader br;
         try {
             URL apiUrl = new URL("https://gitlab.com/api/v4/projects/9264549/releases");
diff --git a/src/main/java/es/kauron/jstudy/util/Clock.java b/src/main/java/es/kauron/jstudy/util/Clock.java
index c3b10ab..d4440df 100644
--- a/src/main/java/es/kauron/jstudy/util/Clock.java
+++ b/src/main/java/es/kauron/jstudy/util/Clock.java
@@ -10,7 +10,7 @@ import java.util.TimerTask;
 public class Clock {
     private static final short SEC_TO_MIN = 60;
     private short seconds = 0;
-    private Timer timer = new Timer();
+    private final Timer timer = new Timer();
     private TimerTask task;
     private final StringProperty time = new SimpleStringProperty();