diff --git a/Include/intrcheck.h b/Include/intrcheck.h
index 68d4977..886dbed 100644
--- a/Include/intrcheck.h
+++ b/Include/intrcheck.h
@@ -1,6 +1,6 @@
 /***********************************************************
-Copyright 1991, 1992 by Stichting Mathematisch Centrum, Amsterdam, The
-Netherlands.
+Copyright 1991, 1992, 1993 by Stichting Mathematisch Centrum,
+Amsterdam, The Netherlands.
 
                         All Rights Reserved