diff --git a/lib/isc/include/isc/platform.h.in b/lib/isc/include/isc/platform.h.in
index 51151583da..79bc895658 100644
--- a/lib/isc/include/isc/platform.h.in
+++ b/lib/isc/include/isc/platform.h.in
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: platform.h.in,v 1.18 2001/01/09 21:57:20 bwelling Exp $ */
+/* $Id: platform.h.in,v 1.19 2001/01/23 04:47:55 marka Exp $ */
 
 #ifndef ISC_PLATFORM_H
 #define ISC_PLATFORM_H 1
@@ -132,6 +132,11 @@
  */
 @ISC_PLATFORM_USETHREADS@
 
+/*
+ * Defined if unistd.h does not cause fd_set to be delared.
+ */
+@ISC_PLATFORM_NEEDSYSSELECTH@
+
 /*
  * Tell emacs to use C mode for this file.
  *
diff --git a/lib/lwres/include/lwres/platform.h.in b/lib/lwres/include/lwres/platform.h.in
index 193aa467e1..4bf5d8e62d 100644
--- a/lib/lwres/include/lwres/platform.h.in
+++ b/lib/lwres/include/lwres/platform.h.in
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: platform.h.in,v 1.10 2001/01/09 21:59:50 bwelling Exp $ */
+/* $Id: platform.h.in,v 1.11 2001/01/23 04:47:56 marka Exp $ */
 
 #ifndef LWRES_PLATFORM_H
 #define LWRES_PLATFORM_H 1
@@ -62,4 +62,9 @@
  */
 @LWRES_PLATFORM_HAVEINADDR6@
 
+/*
+ * Defined if unistd.h does not cause fd_set to be delared.
+ */
+@LWRES_PLATFORM_NEEDSYSSELECTH@
+
 #endif /* LWRES_PLATFORM_H */