--- a/src/test/test_memory_crypto.py	Thu Jun 12 15:56:41 2014 +0200
+++ b/src/test/test_memory_crypto.py	Thu Jun 12 15:57:22 2014 +0200
@@ -34,14 +34,18 @@
 
     def test_encrypt_decrypt(self):
         d_list = []
+
+        def test(key, message):
+            d = BlockCipher.encrypt(key, message)
+            d.addCallback(lambda ciphertext: BlockCipher.decrypt(key, ciphertext))
+            d.addCallback(lambda decrypted: self.assertEqual(message, decrypted))
+            d_list.append(d)
+
         for key_len in (0, 2, 8, 10, 16, 24, 30, 32, 40):
             key = urandom(key_len)
             for message_len in (0, 2, 16, 24, 32, 100):
                 message = urandom(message_len)
-                d = BlockCipher.encrypt(key, message)
-                d.addCallback(lambda ciphertext: lambda key, cipher: BlockCipher.decrypt(key, ciphertext))
-                d.addCallback(lambda decrypted: lambda message, decrypted: self.assertEqual(message, decrypted))
-                d_list.append(d)
+                test(key, message)
         return defer.DeferredList(d_list)
 
     def test_hash_verify(self):