diff --git a/core/java/com/android/internal/alsa/AlsaDevicesParser.java b/core/java/com/android/internal/alsa/AlsaDevicesParser.java
index 3d78a2c27bf49..52037235d5abc 100644
--- a/core/java/com/android/internal/alsa/AlsaDevicesParser.java
+++ b/core/java/com/android/internal/alsa/AlsaDevicesParser.java
@@ -184,7 +184,7 @@ public class AlsaDevicesParser {
         }
     }
 
-    private ArrayList<AlsaDeviceRecord> mDeviceRecords = new ArrayList<AlsaDeviceRecord>();
+    private final ArrayList<AlsaDeviceRecord> mDeviceRecords = new ArrayList<AlsaDeviceRecord>();
 
     public AlsaDevicesParser() {}
 
diff --git a/core/java/com/android/internal/alsa/LineTokenizer.java b/core/java/com/android/internal/alsa/LineTokenizer.java
index 43047a91ce377..b395da9307e54 100644
--- a/core/java/com/android/internal/alsa/LineTokenizer.java
+++ b/core/java/com/android/internal/alsa/LineTokenizer.java
@@ -23,7 +23,7 @@ package com.android.internal.alsa;
 public class LineTokenizer {
     public static final int kTokenNotFound = -1;
 
-    private String mDelimiters = "";
+    private final String mDelimiters;
 
     public LineTokenizer(String delimiters) {
         mDelimiters = delimiters;
diff --git a/services/usb/java/com/android/server/usb/UsbAudioDevice.java b/services/usb/java/com/android/server/usb/UsbAudioDevice.java
index bdd28e4fc3265..70d1fc6913b52 100644
--- a/services/usb/java/com/android/server/usb/UsbAudioDevice.java
+++ b/services/usb/java/com/android/server/usb/UsbAudioDevice.java
@@ -20,10 +20,10 @@ public final class UsbAudioDevice {
     private static final String TAG = "UsbAudioDevice";
     protected static final boolean DEBUG = false;
 
-    public int mCard;
-    public int mDevice;
-    public boolean mHasPlayback;
-    public boolean mHasCapture;
+    public final int mCard;
+    public final int mDevice;
+    public final boolean mHasPlayback;
+    public final boolean mHasCapture;
 
     // Device "class" flags
     public static final int kAudioDeviceClassMask = 0x00FFFFFF;
@@ -34,7 +34,7 @@ public final class UsbAudioDevice {
     public static final int kAudioDeviceMetaMask = 0xFF000000;
     public static final int kAudioDeviceMeta_Alsa = 0x80000000;
     // This member is a combination of the above bit-flags
-    public int mDeviceClass;
+    public final int mDeviceClass;
 
     public String mDeviceName = "";
     public String mDeviceDescription = "";