diff --git a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/NativeAudioMacHandler.java b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/NativeAudioMacHandler.java
index 0e94b7cbc3e8cea525918de0eed9cd6bf12a433f..82507228ff7cf523fb50fa2a799baf54251488ca 100644
--- a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/NativeAudioMacHandler.java
+++ b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/NativeAudioMacHandler.java
@@ -20,14 +20,14 @@ public class NativeAudioMacHandler extends AudioHandler implements Peakable, See
 
 	public static final String SOUND_CARD = "SoundCardMac";
 
-	private ObjectProperty<Duration> positionProperty;
-	private ObjectProperty<Duration> durationProperty;
+	private final ObjectProperty<Duration> positionProperty;
+	private final ObjectProperty<Duration> durationProperty;
 	private boolean isLoaded;
 
-	private DoubleProperty leftPeak;
-	private DoubleProperty rightPeak;
+	private final DoubleProperty leftPeak;
+	private final DoubleProperty rightPeak;
 
-	private AVAudioPlayerBridge bridge;
+	private final AVAudioPlayerBridge bridge;
 
 	NativeAudioMacHandler(PadContent content) {
 		super(content);
diff --git a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/NativeAudioMacHandlerFactory.java b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/NativeAudioMacHandlerFactory.java
index 732b79ac4f6f405700410fc48ba279b620e235d0..5258e5534fb462d02daa3c728e6d98ee493b578a 100644
--- a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/NativeAudioMacHandlerFactory.java
+++ b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/NativeAudioMacHandlerFactory.java
@@ -15,8 +15,8 @@ import java.util.Optional;
 
 public class NativeAudioMacHandlerFactory extends AudioHandlerFactory {
 
-	private List<NativeAudioMacHandler> handlers = new ArrayList<>();
-	private AVAudioPlayerBridgeDelegate bridgeDelegate = new AVAudioPlayerBridgeDelegate(this);
+	private final List<NativeAudioMacHandler> handlers = new ArrayList<>();
+	private final AVAudioPlayerBridgeDelegate bridgeDelegate = new AVAudioPlayerBridgeDelegate(this);
 
 	public Optional<NativeAudioMacHandler> getHandlerByBridge(AVAudioPlayerBridge bridge) {
 		return handlers.stream().filter(handler -> handler.getBridge().equals(bridge)).findFirst();
diff --git a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/delegate/AVAudioPlayerBridgeDelegate.java b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/delegate/AVAudioPlayerBridgeDelegate.java
index cdd746b7f027117362a8cdea555b7fbb31d267eb..a0ad54a505015d0421ce863e5a09b98870bd48b9 100644
--- a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/delegate/AVAudioPlayerBridgeDelegate.java
+++ b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/mac/delegate/AVAudioPlayerBridgeDelegate.java
@@ -12,7 +12,7 @@ import java.util.Optional;
 
 public class AVAudioPlayerBridgeDelegate implements AVAudioPlayerBridge.NativeAudioDelegate {
 
-	private NativeAudioMacHandlerFactory factory;
+	private final NativeAudioMacHandlerFactory factory;
 
 	public AVAudioPlayerBridgeDelegate(NativeAudioMacHandlerFactory factory) {
 		this.factory = factory;