diff --git a/src/libstrongswan/crypto/rsa/rsa_public_key.h b/src/libstrongswan/crypto/rsa/rsa_public_key.h
index f1d45cc4f..02300b5c2 100644
--- a/src/libstrongswan/crypto/rsa/rsa_public_key.h
+++ b/src/libstrongswan/crypto/rsa/rsa_public_key.h
@@ -19,6 +19,8 @@
  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * for more details.
+ *
+ * RCSID $Id$
  */
 
 #ifndef RSA_PUBLIC_KEY_H_