diff --git a/OpenPGP-Keychain-API-Demo/src/org/sufficientlysecure/keychain/demo/CryptoProviderDemoActivity.java b/OpenPGP-Keychain-API-Demo/src/org/sufficientlysecure/keychain/demo/CryptoProviderDemoActivity.java
index ab5795c1c..7bfd72540 100644
--- a/OpenPGP-Keychain-API-Demo/src/org/sufficientlysecure/keychain/demo/CryptoProviderDemoActivity.java
+++ b/OpenPGP-Keychain-API-Demo/src/org/sufficientlysecure/keychain/demo/CryptoProviderDemoActivity.java
@@ -103,9 +103,11 @@ public class CryptoProviderDemoActivity extends Activity {
                 @Override
                 public void run() {
                     mMessage.setText(new String(outputBytes));
-                    Toast.makeText(CryptoProviderDemoActivity.this,
-                            "signature result:\n" + signatureResult.toString(), Toast.LENGTH_LONG)
-                            .show();
+                    if (signatureResult != null) {
+                        Toast.makeText(CryptoProviderDemoActivity.this,
+                                "signature result:\n" + signatureResult.toString(),
+                                Toast.LENGTH_LONG).show();
+                    }
                 }
             });