diff --git a/app/src/main/java/org/thoughtcrime/securesms/webrtc/audio/SignalAudioHandler.kt b/app/src/main/java/org/thoughtcrime/securesms/webrtc/audio/SignalAudioHandler.kt
index 89eba2a3aa..7ca44f46dc 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/webrtc/audio/SignalAudioHandler.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/webrtc/audio/SignalAudioHandler.kt
@@ -15,7 +15,7 @@ class SignalAudioHandler(looper: Looper) : Handler(looper) {
         }
     }
 
-    fun isOnHandler(): Boolean {
+    private fun isOnHandler(): Boolean {
         return Looper.myLooper() == looper
     }
 }
diff --git a/app/src/main/java/org/thoughtcrime/securesms/webrtc/audio/SignalAudioManager.kt b/app/src/main/java/org/thoughtcrime/securesms/webrtc/audio/SignalAudioManager.kt
index 6eb1304430..229cbd13dd 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/webrtc/audio/SignalAudioManager.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/webrtc/audio/SignalAudioManager.kt
@@ -34,9 +34,9 @@ class SignalAudioManager(private val context: Context,
                          private val androidAudioManager: AudioManagerCompat) {
 
     private var commandAndControlThread: HandlerThread? = HandlerThread("call-audio", ThreadUtils.PRIORITY_IMPORTANT_BACKGROUND_THREAD).apply { start() }
-    private var handler: SignalAudioHandler? = SignalAudioHandler(commandAndControlThread!!.looper)
+    private var handler: SignalAudioHandler = SignalAudioHandler(commandAndControlThread!!.looper)
 
-    private var signalBluetoothManager: SignalBluetoothManager = SignalBluetoothManager(context, this, androidAudioManager, handler!!)
+    private var signalBluetoothManager: SignalBluetoothManager = SignalBluetoothManager(context, this, androidAudioManager, handler)
 
     private var state: State = State.UNINITIALIZED
 
@@ -63,7 +63,7 @@ class SignalAudioManager(private val context: Context,
     private var wiredHeadsetReceiver: WiredHeadsetReceiver? = null
 
     fun handleCommand(command: AudioManagerCommand) {
-        handler?.post {
+        handler.post {
             when (command) {
                 is AudioManagerCommand.Initialize -> initialize()
                 is AudioManagerCommand.UpdateAudioDeviceState -> updateAudioDeviceState()
@@ -107,7 +107,7 @@ class SignalAudioManager(private val context: Context,
     }
 
     fun shutdown() {
-        handler!!.post {
+        handler.post {
             stop(false)
             if (commandAndControlThread != null) {
                 Log.i(TAG, "Shutting down command and control")
@@ -172,7 +172,7 @@ class SignalAudioManager(private val context: Context,
     }
 
     private fun updateAudioDeviceState() {
-        handler!!.assertHandlerThread()
+        handler.assertHandlerThread()
 
         Log.i(
                 TAG,
@@ -362,7 +362,7 @@ class SignalAudioManager(private val context: Context,
             val pluggedIn = intent.getIntExtra("state", 0) == 1
             val hasMic = intent.getIntExtra("microphone", 0) == 1
 
-            handler?.post { onWiredHeadsetChange(pluggedIn, hasMic) }
+            handler.post { onWiredHeadsetChange(pluggedIn, hasMic) }
         }
     }