diff --git a/PlayWallCore/src/main/java/de/tobias/playpad/audio/AudioCapability.java b/PlayWallCore/src/main/java/de/tobias/playpad/audio/AudioCapability.java
index c8db038e85e1b12b53a665a4fd4995b5c97d30fe..5fb29e5373d451e77f55ec95885e075859ce859e 100644
--- a/PlayWallCore/src/main/java/de/tobias/playpad/audio/AudioCapability.java
+++ b/PlayWallCore/src/main/java/de/tobias/playpad/audio/AudioCapability.java
@@ -11,10 +11,10 @@ public class AudioCapability {
 	public static final AudioCapability EQUALIZER = new AudioCapability("EQUALIZER", Equalizeable.class);
 	public static final AudioCapability SOUNDCARD = new AudioCapability("SOUNDCARD", Soundcardable.class);
 
-	private String nameKey;
-	private Class<? extends AudioFeature> clazz;
+	private final String nameKey;
+	private final Class<? extends AudioFeature> clazz;
 
-	private static List<AudioCapability> audioCapabilityList;
+	private static final List<AudioCapability> audioCapabilityList;
 
 	static {
 		audioCapabilityList = new ArrayList<>();
diff --git a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/windows/NativeAudioWinHandler.java b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/windows/NativeAudioWinHandler.java
index e0e75d8214d02545871f708dc5f0cacfe6bf9019..399cc42c4f02033e6d3efca1d96c4daaf987bc5b 100644
--- a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/windows/NativeAudioWinHandler.java
+++ b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/audio/windows/NativeAudioWinHandler.java
@@ -26,11 +26,11 @@ public class NativeAudioWinHandler extends AudioHandler implements Soundcardable
 	static final String SOUND_CARD = "SoundCard";
 
 	private NativeAudio audioHandler;
-	private ObjectProperty<Duration> durationProperty;
-	private ObjectProperty<Duration> positionProperty;
+	private final ObjectProperty<Duration> durationProperty;
+	private final ObjectProperty<Duration> positionProperty;
 
 	private static Thread positionThread;
-	private static List<NativeAudioWinHandler> playedHandlers = new ArrayList<>();
+	private static final List<NativeAudioWinHandler> playedHandlers = new ArrayList<>();
 	private static final int SLEEP_TIME_POSITION = 50;
 
 	static {
diff --git a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/plugin/NativeAudioPathType.java b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/plugin/NativeAudioPathType.java
index 771db0fe9805a4aab1d286d97bd42c8acb9a61c8..1cba1f2a019dd1a84584c7d0bb785a252f822d1e 100644
--- a/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/plugin/NativeAudioPathType.java
+++ b/PlayWallPlugins/PlayWallPluginNativeAudio/src/main/java/de/tobias/playpad/plugin/NativeAudioPathType.java
@@ -7,7 +7,7 @@ public enum NativeAudioPathType implements ContainerPathType {
 
 	AUDIO(PathType.LIBRARY.getFolder() + "/Audio");
 
-	private String folder;
+	private final String folder;
 
 	NativeAudioPathType(String folder) {
 		this.folder = folder;