diff --git a/mps/src/testlib.h b/mps/src/testlib.h
index 801ef2331e0..e95f4667800 100644
--- a/mps/src/testlib.h
+++ b/mps/src/testlib.h
@@ -1,8 +1,8 @@
 /*  ==== TEST LIBRARY ====
  *
- *  $HopeName: MMsrc!testlib.h(trunk.8) $
+ *  $HopeName: MMsrc!testlib.h(trunk.9) $
  *
- *  Copyright (C) 1995, 1997, 1998 Harlequin Group, all rights reserved
+ *  Copyright (C) 1995, 1998.  Harlequin Group plc.  All rights reserved.
  *
  *  This is a library of functions that unit test developers might find
  *  useful.  We hope they enhance your programming pleasure.
@@ -17,6 +17,13 @@
 
 #include "mps.h"
 
+#include <stdio.h>
+/* On SunOS, need ossu.h as well */
+#include "mpstd.h"
+#ifdef MPS_OS_SU
+#include "ossu.h"
+#endif
+
 
 /* Suppress Visual C warnings at warning level 4, */
 /* see mail.richard.1997-09-25.13-26. */