diff --git a/ghc/rts/RtsUtils.c b/ghc/rts/RtsUtils.c
index 2b929c9dfb374be5794a12dba35e8b7c9a1a7dee..23bf0d62465b9a2c1e238e8ba9bde740732429bf 100644
--- a/ghc/rts/RtsUtils.c
+++ b/ghc/rts/RtsUtils.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: RtsUtils.c,v 1.14 2000/03/31 03:09:36 hwloidl Exp $
+ * $Id: RtsUtils.c,v 1.15 2000/04/14 14:07:43 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -7,6 +7,9 @@
  *
  * ---------------------------------------------------------------------------*/
 
+/* gettimeofday isn't POSIX */
+#define NON_POSIX_SOURCE
+
 #include "Rts.h"
 #include "RtsTypes.h"
 #include "RtsAPI.h"