1 files changed, 6 insertions, 1 deletions
diff --git a/ijs/ijs.h b/ijs/ijs.h
index 584c6ab1..9a03fdf4 100644
--- a/ijs/ijs.h
+++ b/ijs/ijs.h
@@ -1,5 +1,5 @@
 /**
- * Copyright (C) 2001-2019 Artifex Software, Inc.
+ * Copyright (C) 2001-2020 Artifex Software, Inc.
  *
  * Permission is hereby granted, free of charge, to any person
  * obtaining a copy of this software and associated documentation
@@ -22,6 +22,9 @@
  * SOFTWARE.
 **/
 
+#ifndef ijs_h_INCLUDED
+#define ijs_h_INCLUDED
+
 /* This file contains common data types for IJS */
 
 /* IJS_VERSION is decimal version number times 100 */
@@ -122,3 +125,5 @@ ijs_recv_int (IjsRecvChan *ch, int *val);
 
 int
 ijs_recv_block (IjsRecvChan *ch, char *buf, int buf_size);
+
+#endif