diff --git a/epan/dissectors/packet-shim6.c b/epan/dissectors/packet-shim6.c
index 59b3bf6146..9410ebec69 100644
--- a/epan/dissectors/packet-shim6.c
+++ b/epan/dissectors/packet-shim6.c
@@ -6,6 +6,8 @@
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  *
+ * RFC 5533
+ *
  * SHIM6 support added by Matthijs Mekking <matthijs@NLnetLabs.nl>
  */