diff --git a/tests/test_fernet.py b/tests/test_fernet.py
index b0f22f0..a42011a 100644
--- a/tests/test_fernet.py
+++ b/tests/test_fernet.py
@@ -61,3 +61,10 @@
             f.encrypt(six.u(""))
         with pytest.raises(TypeError):
             f.decrypt(six.u(""))
+
+    @pytest.mark.parametrize("message", [b"", b"Abc!", b"\x00\xFF\x00\x80"])
+    def test_roundtrips(self, message):
+        f = Fernet(b"\x00" * 32)
+        ciphertext = f.encrypt(message)
+        plaintext = f.decrypt(ciphertext)
+        assert plaintext == message