1 files changed, 20 insertions, 0 deletions
diff --git a/base/ets.h b/base/ets.h
index 08ad62057..f6471bb04 100644
--- a/base/ets.h
+++ b/base/ets.h
@@ -1,3 +1,21 @@
+/* Copyright (C) 2001-2018 Artifex Software, Inc.
+   All Rights Reserved.
+
+   This software is provided AS-IS with no warranty, either express or
+   implied.
+
+   This software is distributed under license and may not be copied,
+   modified or distributed except as expressly authorized under the terms
+   of the license contained in the file LICENSE in this distribution.
+
+   Refer to licensing information at http://www.artifex.com or contact
+   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
+   CA 94945, U.S.A., +1(415)492-9861, for further information.
+*/
+
+#ifndef ets_h_INCLUDED
+#  define ets_h_INCLUDED
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -114,3 +132,5 @@ ets_free(void *malloc_arg, void *p);
 #ifdef __cplusplus
 }
 #endif
+
+#endif