3 files changed, 4 insertions, 4 deletions
diff --git a/src/main/java/org/traccar/WindowsService.java b/src/main/java/org/traccar/WindowsService.java
index f233337a7..08eba25a6 100644
--- a/src/main/java/org/traccar/WindowsService.java
+++ b/src/main/java/org/traccar/WindowsService.java
@@ -170,7 +170,7 @@ public abstract class WindowsService {
 
     public abstract void run();
 
-    private class ServiceMain implements SERVICE_MAIN_FUNCTION {
+    private final class ServiceMain implements SERVICE_MAIN_FUNCTION {
 
         public void callback(int dwArgc, Pointer lpszArgv) {
             ServiceControl serviceControl = new ServiceControl();
@@ -203,7 +203,7 @@ public abstract class WindowsService {
 
     }
 
-    private class ServiceControl implements HandlerEx {
+    private final class ServiceControl implements HandlerEx {
 
         public int callback(int dwControl, int dwEventType, Pointer lpEventData, Pointer lpContext) {
             switch (dwControl) {
diff --git a/src/main/java/org/traccar/database/DeviceLookupService.java b/src/main/java/org/traccar/database/DeviceLookupService.java
index 6ec6841a1..90d23531e 100644
--- a/src/main/java/org/traccar/database/DeviceLookupService.java
+++ b/src/main/java/org/traccar/database/DeviceLookupService.java
@@ -49,7 +49,7 @@ public class DeviceLookupService {
 
     private final boolean throttlingEnabled;
 
-    private static class IdentifierInfo {
+    private static final class IdentifierInfo {
         private long lastQuery;
         private long delay;
         private Timeout timeout;
diff --git a/src/main/java/org/traccar/protocol/Mta6ProtocolDecoder.java b/src/main/java/org/traccar/protocol/Mta6ProtocolDecoder.java
index 896c7a2d2..9704cf099 100644
--- a/src/main/java/org/traccar/protocol/Mta6ProtocolDecoder.java
+++ b/src/main/java/org/traccar/protocol/Mta6ProtocolDecoder.java
@@ -96,7 +96,7 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
 
     }
 
-    private static class TimeReader extends FloatReader {
+    private static final class TimeReader extends FloatReader {
 
         private long weekNumber;