diff --git a/util/cpp/expression.g b/util/cpp/expression.g
index 109b56441..0674f15f5 100644
--- a/util/cpp/expression.g
+++ b/util/cpp/expression.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".
+ */
 /*	EXPRESSION SYNTAX PARSER	*/
 
 %lexical	LLlex;