diff --git a/src/android/FirebasePlugin.java b/src/android/FirebasePlugin.java
index 6a227dba5..ed8480268 100755
--- a/src/android/FirebasePlugin.java
+++ b/src/android/FirebasePlugin.java
@@ -18,6 +18,8 @@
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigSettings;
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigValue;
 import com.google.firebase.crash.FirebaseCrash;
+import com.google.firebase.auth.PhoneAuthCredential;
+import com.google.firebase.auth.PhoneAuthProvider;
 import me.leolin.shortcutbadger.ShortcutBadger;
 import org.apache.cordova.CallbackContext;
 import org.apache.cordova.CordovaPlugin;
@@ -43,6 +45,8 @@ public class FirebasePlugin extends CordovaPlugin {
     private static CallbackContext notificationCallbackContext;
     private static CallbackContext tokenRefreshCallbackContext;
 
+    private PhoneAuthProvider.OnVerificationStateChangedCallbacks mCallbacks;
+
     @Override
     protected void pluginInitialize() {
         final Context context = this.cordova.getActivity().getApplicationContext();