diff --git a/rxp-hpp-android/src/main/java/com/realexpayments/hpp/HPPManagerFragment.java b/rxp-hpp-android/src/main/java/com/realexpayments/hpp/HPPManagerFragment.java
index c83ce81..47b21f4 100644
--- a/rxp-hpp-android/src/main/java/com/realexpayments/hpp/HPPManagerFragment.java
+++ b/rxp-hpp-android/src/main/java/com/realexpayments/hpp/HPPManagerFragment.java
@@ -141,7 +141,7 @@ private String getRelativePathEncoded(String urlString) {
 
     @Override
     public void onDestroy() {
-        if (!isResultReceived) {
+        if (!isResultReceived && mListener != null) {
             mListener.hppManagerCancelled();
         }
         mListener = null;
@@ -165,7 +165,9 @@ public boolean onKey(View v, int keyCode, KeyEvent event) {
                 if (keyCode == KeyEvent.KEYCODE_BACK && webView.canGoBack()) {
                     if (!isResultReceived) {
                         webView.goBack();
-                        mListener.hppManagerCancelled();
+                        if (mListener != null) {
+                            mListener.hppManagerCancelled();
+                        }
                         isResultReceived = true;
                     }
                     return false;
@@ -322,6 +324,9 @@ public void callbackHandler(String data, String url) {
                                 @Override
                                 public void success(Response s, Response response) {
                                     String msg = new String(((TypedByteArray) response.getBody()).getBytes());
+                                    if (mListener == null) {
+                                        return;
+                                    }
                                     Method[] methods = mListener.getClass().getDeclaredMethods();
                                     for (int i = 0; i < methods.length; i++) {
                                         if (methods[i].getName().equals(HPPManagerListener.HPP_MANAGER_COMPLETED_WITH_RESULT)) {