diff --git a/README.md b/README.md
index 812d239e..1146418c 100644
--- a/README.md
+++ b/README.md
@@ -137,6 +137,8 @@ Setup FCM
 You must download the file `google-services.json` from the Firebase console.
 It contains keys and settings for all your applications under Firebase. This library obtains the resource `senderID` for registering for remote GCM from that file.
 
+Then follow these step by step https://firebase.google.com/docs/android/setup
+
 #### `android/build.gradle`
 
 ```groovy
@@ -152,6 +154,17 @@ buildscript {
 apply plugin: 'com.google.gms.google-services'
 ```
 
+#### `android/app/build.gradle`
+
+```groovy
+dependencies {    
+    implementation platform('com.google.firebase:firebase-bom:26.4.0')
+    implementation 'com.google.firebase:firebase-messaging'
+    implementation 'com.google.firebase:firebase-analytics'
+}
+```
+
+
 #### `AndroidManifest.xml`
 
 ```xml
diff --git a/android/build.gradle b/android/build.gradle
index fe752fa4..0fc7d2e9 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -58,6 +58,6 @@ dependencies {
     implementation 'com.twilio:voice-android:4.5.0'
     implementation "com.android.support:appcompat-v7:$supportLibVersion"
     implementation 'com.facebook.react:react-native:+'
-    implementation 'com.google.firebase:firebase-messaging:17.6.+'
+    implementation 'com.google.firebase:firebase-messaging:21.0.+'
     testImplementation 'junit:junit:4.12'
 }
diff --git a/android/src/main/java/com/hoxfon/react/RNTwilioVoice/fcm/VoiceFirebaseMessagingService.java b/android/src/main/java/com/hoxfon/react/RNTwilioVoice/fcm/VoiceFirebaseMessagingService.java
index 520b77f1..d326b179 100644
--- a/android/src/main/java/com/hoxfon/react/RNTwilioVoice/fcm/VoiceFirebaseMessagingService.java
+++ b/android/src/main/java/com/hoxfon/react/RNTwilioVoice/fcm/VoiceFirebaseMessagingService.java
@@ -37,6 +37,14 @@ public class VoiceFirebaseMessagingService extends FirebaseMessagingService {
 
     private CallNotificationManager callNotificationManager;
 
+    private FirebaseMessagingService mFirebaseServiceDelegate;
+
+    public VoiceFirebaseMessagingService(FirebaseMessagingService delegate) {
+        super();
+        this.mFirebaseServiceDelegate = delegate;
+        callNotificationManager = new CallNotificationManager();
+    }
+
     @Override
     public void onCreate() {
         super.onCreate();
@@ -66,7 +74,7 @@ public void onMessageReceived(RemoteMessage remoteMessage) {
         // Check if message contains a data payload.
         if (remoteMessage.getData().size() > 0) {
             Map<String, String> data = remoteMessage.getData();
-
+            final FirebaseMessagingService serviceRef = (this.mFirebaseServiceDelegate == null) ? this : this.mFirebaseServiceDelegate;
             // If notification ID is not provided by the user for push notification, generate one at random
             Random randomNumberGenerator = new Random(System.currentTimeMillis());
             final int notificationId = randomNumberGenerator.nextInt();
@@ -82,7 +90,7 @@ public void onCallInvite(final CallInvite callInvite) {
                     handler.post(new Runnable() {
                         public void run() {
                             // Construct and load our normal React JS code bundle
-                            ReactInstanceManager mReactInstanceManager = ((ReactApplication) getApplication()).getReactNativeHost().getReactInstanceManager();
+                            ReactInstanceManager mReactInstanceManager = ((ReactApplication)serviceRef.getApplication()).getReactNativeHost().getReactInstanceManager();
                             ReactContext context = mReactInstanceManager.getCurrentReactContext();
                             // If it's constructed, send a notification
                             if (context != null) {