diff --git a/src/test/java/com/pusher/client/crypto/nacl/SecretBoxOpenerTest.java b/src/test/java/com/pusher/client/crypto/nacl/SecretBoxOpenerTest.java
index 5b02c3b7..46077dc6 100644
--- a/src/test/java/com/pusher/client/crypto/nacl/SecretBoxOpenerTest.java
+++ b/src/test/java/com/pusher/client/crypto/nacl/SecretBoxOpenerTest.java
@@ -11,8 +11,8 @@ public class SecretBoxOpenerTest {
 
     byte[] key = Base64.decode("6071zp2l/GPnDPDXNWTJDHyIZ8pZMvQrYsa4xuTKK2c=");
 
-    byte[] nonce = Base64.decode("xsbOS0KylAV2ziTDHrP/7rSFqpCOah3p");
     byte[] cipher = Base64.decode("tvttPE2PRQp0bWDmaPyiEU8YJGztmTvTN77OoPwftTNTdDgJXwxHQPE=");
+    byte[] nonce = Base64.decode("xsbOS0KylAV2ziTDHrP/7rSFqpCOah3p");
 
     SecretBoxOpener subject;
 
@@ -35,4 +35,11 @@ public void openFailsForTamperedCipher() {
 
         subject.open(tamperedCipher, nonce);
     }
+
+    @Test(expected = NullPointerException.class)
+    public void openFailsAfterClearKey() {
+        subject.clearKey();
+
+        subject.open(cipher, nonce);
+    }
 }
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