diff --git a/util/topgen/topgen.g b/util/topgen/topgen.g
index 1b27f0ee..96dfd32f 100644
--- a/util/topgen/topgen.g
+++ b/util/topgen/topgen.g
@@ -1,3 +1,7 @@
+/*
+ * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
+ * See the copyright notice in the ACK home directory, in the file "Copyright".
+ */
 /* t o p g e n . g
  *
  * Grammar of optimizer description, and some code generation