diff --git a/app/build.gradle b/app/build.gradle
index 7633c13..643628d 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -30,6 +30,8 @@ android {
 }
 
 dependencies {
+    //butter knife
+    implementation libs.firebase.messaging
     implementation libs.core
     //The mpesa Library
     implementation project(':mpesa')
diff --git a/app/src/main/java/com/mpesaandroidintegration/mpesaintegrationandroid/MPESAInstanceIDService.java b/app/src/main/java/com/mpesaandroidintegration/mpesaintegrationandroid/MPESAInstanceIDService.java
index 26e8f2c..c437634 100644
--- a/app/src/main/java/com/mpesaandroidintegration/mpesaintegrationandroid/MPESAInstanceIDService.java
+++ b/app/src/main/java/com/mpesaandroidintegration/mpesaintegrationandroid/MPESAInstanceIDService.java
@@ -2,12 +2,15 @@
 
 import android.content.SharedPreferences;
 import android.util.Log;
+
+import androidx.annotation.NonNull;
+
 import com.google.firebase.messaging.FirebaseMessagingService;
 
 public class MPESAInstanceIDService extends FirebaseMessagingService {
     private static final String TAG = "MPESAInstanceIDService";
     @Override
-    public void onNewToken(String token) {
+    public void onNewToken(@NonNull String token) {
         Log.d(TAG, "Refreshed token: " + token);
 
         // Save token to shared preferences