diff --git a/src/main/java/eu/siacs/conversations/entities/MucOptions.java b/src/main/java/eu/siacs/conversations/entities/MucOptions.java
index 67657159a..83b0c76fb 100644
--- a/src/main/java/eu/siacs/conversations/entities/MucOptions.java
+++ b/src/main/java/eu/siacs/conversations/entities/MucOptions.java
@@ -37,7 +37,7 @@ public class MucOptions {
     private final Conversation conversation;
     public OnRenameListener onRenameListener = null;
     private boolean mAutoPushConfiguration = true;
-    private Account account;
+    private final Account account;
     private ServiceDiscoveryResult serviceDiscoveryResult;
     private boolean isOnline = false;
     private Error error = Error.NONE;
diff --git a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
index 0f2423f63..361c1a904 100644
--- a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
+++ b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
@@ -206,21 +206,21 @@ public class XmppConnectionService extends Service {
         }
     };
     public DatabaseBackend databaseBackend;
-    private ReplacingSerialSingleThreadExecutor mContactMergerExecutor = new ReplacingSerialSingleThreadExecutor("ContactMerger");
+    private final ReplacingSerialSingleThreadExecutor mContactMergerExecutor = new ReplacingSerialSingleThreadExecutor("ContactMerger");
     private long mLastActivity = 0;
-    private FileBackend fileBackend = new FileBackend(this);
+    private final FileBackend fileBackend = new FileBackend(this);
     private MemorizingTrustManager mMemorizingTrustManager;
-    private NotificationService mNotificationService = new NotificationService(this);
-    private ChannelDiscoveryService mChannelDiscoveryService = new ChannelDiscoveryService(this);
-    private ShortcutService mShortcutService = new ShortcutService(this);
-    private AtomicBoolean mInitialAddressbookSyncCompleted = new AtomicBoolean(false);
-    private AtomicBoolean mForceForegroundService = new AtomicBoolean(false);
-    private AtomicBoolean mForceDuringOnCreate = new AtomicBoolean(false);
-    private AtomicReference<OngoingCall> ongoingCall = new AtomicReference<>();
-    private OnMessagePacketReceived mMessageParser = new MessageParser(this);
-    private OnPresencePacketReceived mPresenceParser = new PresenceParser(this);
-    private IqParser mIqParser = new IqParser(this);
-    private MessageGenerator mMessageGenerator = new MessageGenerator(this);
+    private final NotificationService mNotificationService = new NotificationService(this);
+    private final ChannelDiscoveryService mChannelDiscoveryService = new ChannelDiscoveryService(this);
+    private final ShortcutService mShortcutService = new ShortcutService(this);
+    private final AtomicBoolean mInitialAddressbookSyncCompleted = new AtomicBoolean(false);
+    private final AtomicBoolean mForceForegroundService = new AtomicBoolean(false);
+    private final AtomicBoolean mForceDuringOnCreate = new AtomicBoolean(false);
+    private final AtomicReference<OngoingCall> ongoingCall = new AtomicReference<>();
+    private final OnMessagePacketReceived mMessageParser = new MessageParser(this);
+    private final OnPresencePacketReceived mPresenceParser = new PresenceParser(this);
+    private final IqParser mIqParser = new IqParser(this);
+    private final MessageGenerator mMessageGenerator = new MessageGenerator(this);
     public OnContactStatusChanged onContactStatusChanged = (contact, online) -> {
         Conversation conversation = find(getConversations(), contact);
         if (conversation != null) {
@@ -231,14 +231,14 @@ public class XmppConnectionService extends Service {
             }
         }
     };
-    private PresenceGenerator mPresenceGenerator = new PresenceGenerator(this);
+    private final PresenceGenerator mPresenceGenerator = new PresenceGenerator(this);
     private List<Account> accounts;
-    private JingleConnectionManager mJingleConnectionManager = new JingleConnectionManager(this);
-    private HttpConnectionManager mHttpConnectionManager = new HttpConnectionManager(this);
-    private AvatarService mAvatarService = new AvatarService(this);
-    private MessageArchiveService mMessageArchiveService = new MessageArchiveService(this);
-    private PushManagementService mPushManagementService = new PushManagementService(this);
-    private QuickConversationsService mQuickConversationsService = new QuickConversationsService(this);
+    private final JingleConnectionManager mJingleConnectionManager = new JingleConnectionManager(this);
+    private final HttpConnectionManager mHttpConnectionManager = new HttpConnectionManager(this);
+    private final AvatarService mAvatarService = new AvatarService(this);
+    private final MessageArchiveService mMessageArchiveService = new MessageArchiveService(this);
+    private final PushManagementService mPushManagementService = new PushManagementService(this);
+    private final QuickConversationsService mQuickConversationsService = new QuickConversationsService(this);
     private final ConversationsFileObserver fileObserver = new ConversationsFileObserver(
             Environment.getExternalStorageDirectory().getAbsolutePath()
     ) {
diff --git a/src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java b/src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java
index 2924a07eb..25f0dfe1e 100644
--- a/src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java
+++ b/src/main/java/eu/siacs/conversations/ui/adapter/MessageAdapter.java
@@ -87,7 +87,7 @@ public class MessageAdapter extends ArrayAdapter<Message> {
     private final XmppActivity activity;
     private final AudioPlayer audioPlayer;
     private List<String> highlightedTerm = null;
-    private DisplayMetrics metrics;
+    private final DisplayMetrics metrics;
     private OnContactPictureClicked mOnContactPictureClickedListener;
     private OnContactPictureLongClicked mOnContactPictureLongClickedListener;
     private boolean mUseGreenBackground = false;