diff --git a/demo/src/main/java/com/tinder/service/ChatRoomSocketIoService.kt b/demo/src/main/java/com/tinder/service/ChatRoomSocketIoService.kt
index e570a822..1b6fcff3 100644
--- a/demo/src/main/java/com/tinder/service/ChatRoomSocketIoService.kt
+++ b/demo/src/main/java/com/tinder/service/ChatRoomSocketIoService.kt
@@ -4,13 +4,16 @@
 
 package com.tinder.service
 
+import android.annotation.SuppressLint
 import android.app.Notification
 import android.app.NotificationChannel
 import android.app.NotificationManager
 import android.content.Intent
+import android.os.Build
 import android.os.Handler
 import android.os.IBinder
 import android.os.Messenger
+import androidx.core.app.NotificationCompat
 import androidx.lifecycle.LifecycleService
 import com.tinder.R
 import com.tinder.app.socketio.chatroom.api.AddUserTopic
@@ -36,6 +39,7 @@ class ChatRoomSocketIoService : LifecycleService() {
     var incomingMessageCount = 0
     private val messenger = Messenger(IncomingHandler())
 
+    @SuppressLint("CheckResult")
     override fun onCreate() {
         super.onCreate()
 
@@ -73,9 +77,11 @@ class ChatRoomSocketIoService : LifecycleService() {
 
         val notificationManager = getSystemService(NOTIFICATION_SERVICE) as NotificationManager
 
-        val notificationChannel =
-            NotificationChannel(channelId, "Default", NotificationManager.IMPORTANCE_HIGH)
-        notificationManager.createNotificationChannel(notificationChannel)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val notificationChannel =
+                NotificationChannel(channelId, "Default", NotificationManager.IMPORTANCE_HIGH)
+            notificationManager.createNotificationChannel(notificationChannel)
+        }
 
         Timber.d("chatroom scarlet created")
 
@@ -94,37 +100,42 @@ class ChatRoomSocketIoService : LifecycleService() {
         addUserTopic.observeSocketIoEvent()
             .filter { it is SocketIoEvent.OnConnectionOpened }
             .observeOn(Schedulers.io())
-            .subscribe({
-                addUserTopic.sendAddUser(username)
-
-                Timber.d("chatroom added user: $it")
-                val notification = createNotification {
-                    setContentText("Joined chatroom")
-                }
-                notificationManager.notify(notificationIdCurrentState, notification)
-            }, { e ->
-                Timber.e(e)
-            })
+            .subscribe(
+                {
+                    addUserTopic.sendAddUser(username)
+
+                    Timber.d("chatroom added user: $it")
+                    val notification = createNotification {
+                        setContentText("Joined chatroom")
+                    }
+                    notificationManager.notify(notificationIdCurrentState, notification)
+                },
+                { e ->
+                    Timber.e(e)
+                })
 
         Flowable.fromPublisher(AndroidLifecycle.ofLifecycleServiceStarted(application, this))
-            .subscribe({
+            .subscribe {
                 Timber.d("chatroom lifecycle: $it")
 
                 val notification = createNotification {
                     setContentText("Lifecycle State: $it")
                 }
                 notificationManager.notify(notificationIdCurrentState, notification)
-            })
+            }
 
         Flowable.merge(
-            newMessageTopic.observeNewMessage().map { "${it.username}: ${it.message}" },
-            typingStartedTopic.observeTypingStarted().map { "${it.username} started typing" },
-            typingStoppedTopic.observeTypingStopped().map { "${it.username} stopped typing" }
+            newMessageTopic.observeNewMessage()
+                .map { "${it.username}: ${it.message}" },
+            typingStartedTopic.observeTypingStarted()
+                .map { "${it.username} started typing" },
+            typingStoppedTopic.observeTypingStopped()
+                .map { "${it.username} stopped typing" }
         ).subscribe {
             Timber.d("chatroom new message: $it")
 
             val notification = createNotification {
-                setContentText("$it")
+                setContentText(it)
             }
 
             val notificationId = notificationIdIncomingMessage + incomingMessageCount
@@ -139,8 +150,8 @@ class ChatRoomSocketIoService : LifecycleService() {
         return messenger.binder
     }
 
-    private fun createNotification(builder: Notification.Builder.() -> Unit): Notification {
-        return Notification.Builder(applicationContext, channelId)
+    private fun createNotification(builder: NotificationCompat.Builder.() -> Unit): Notification {
+        return NotificationCompat.Builder(applicationContext, channelId)
             .setSmallIcon(R.drawable.ic_action_info)
             .setWhen(System.currentTimeMillis())
             .setContentTitle("Chat Room")
diff --git a/dependencies.gradle b/dependencies.gradle
index ff72df7b..c7a79c2c 100644
--- a/dependencies.gradle
+++ b/dependencies.gradle
@@ -3,7 +3,7 @@
  */
 
 ext {
-    minSdkVersion = 28
+    minSdkVersion = 24
     minSdkVersionAndroidLifecycle = 19
     targetSdkVersion = 28
     compileSdkVersion = 28
diff --git a/gradle.properties b/gradle.properties
index 2dda6e76..53371d19 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -4,4 +4,4 @@
 
 android.enableJetifier=true
 android.useAndroidX=true
-version=0.2.4-alpha1
+version=0.2.4