--- ray/src/px/ra_ps.c	2004/03/28 20:33:14	2.28
+++ ray/src/px/ra_ps.c	2018/03/20 18:45:04	2.29
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: ra_ps.c,v 2.28 2004/03/28 20:33:14 schorsch Exp $";
+static const char	RCSid[] = "$Id: ra_ps.c,v 2.29 2018/03/20 18:45:04 greg Exp $";
 #endif
 /*
  *  Radiance picture to PostScript file translator -- one way!
@@ -11,6 +11,7 @@ static const char	RCSid[] = "$Id: ra_ps.c,v 2.28 2004/
 #include  <ctype.h>
 
 #include  "platform.h"
+#include  "rtio.h"
 #include  "color.h"
 #include  "resolu.h"