diff --git a/tools/util.c b/tools/util.c
index 9a85161..029719e 100644
--- a/tools/util.c
+++ b/tools/util.c
@@ -4,7 +4,8 @@
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; version 2.
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
 */
 
 #include <stdio.h>
diff --git a/tools/util.h b/tools/util.h
index 608adb6..a179b19 100644
--- a/tools/util.h
+++ b/tools/util.h
@@ -4,7 +4,8 @@
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; version 2.
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
 */
 
 #ifndef _UTIL_H