diff --git a/leakcheck/crypto.py b/leakcheck/crypto.py
index eb00182..07b77e5 100644
--- a/leakcheck/crypto.py
+++ b/leakcheck/crypto.py
@@ -1,3 +1,6 @@
+# Copyright (C) Jean-Paul Calderone
+# See LICENSE for details.
+
 import sys
 
 from OpenSSL.crypto import TYPE_DSA, Error, PKey, X509