diff --git a/ChangeLog b/ChangeLog
index ff5e09e7d..d38e04caf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2004-08-07 Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSPort.m (+initialize), Source/NSPortNameServer.m
+	(systemDefaultPortNameServer): We should be using message ports
+	when we are supposed to be MacOS-X compatible anyway, so check the
+	runtime compatibility setting.  Maybe we should be thinking about
+	changing away from the OpenStep behavior as default, and put a
+	warning into the next release?
+
 2004-08-07 02:26  Alexander Malmberg <alexander@malmberg.org>
 
 	* Source/NSPort.m (+initialize), Source/NSPortNameServer.m
diff --git a/Source/NSPort.m b/Source/NSPort.m
index 2c136092b..7fc3a78f2 100644
--- a/Source/NSPort.m
+++ b/Source/NSPort.m
@@ -34,6 +34,7 @@
 #include "Foundation/NSRunLoop.h"
 #include "Foundation/NSAutoreleasePool.h"
 #include "Foundation/NSUserDefaults.h"
+#include "GSPrivate.h"
 
 
 @class NSMessagePort;
@@ -68,7 +69,8 @@ Class	NSPort_concrete_class;
       NSPort_abstract_class = self;
       /* Must be kept in sync with [NSPortNameServer
       +systemDefaultPortNameServer]. */
-      if ([[NSUserDefaults standardUserDefaults]
+      if (GSUserDefaultsFlag(GSMacOSXCompatible) == YES 
+	|| [[NSUserDefaults standardUserDefaults]
 	boolForKey: @"NSPortIsMessagePort"])
 	{
 	  NSPort_concrete_class = [NSMessagePort class];
diff --git a/Source/NSPortNameServer.m b/Source/NSPortNameServer.m
index ebb78ab3e..c6d98997b 100644
--- a/Source/NSPortNameServer.m
+++ b/Source/NSPortNameServer.m
@@ -30,6 +30,7 @@
 #include "Foundation/NSPortNameServer.h"
 #include "Foundation/NSDebug.h"
 #include "Foundation/NSUserDefaults.h"
+#include "GSPrivate.h"
 
 
 /**
@@ -64,7 +65,8 @@
 + (id) systemDefaultPortNameServer
 {
   /* Must be kept in sync with [NSPort +initialize]. */
-  if ([[NSUserDefaults standardUserDefaults]
+  if (GSUserDefaultsFlag(GSMacOSXCompatible) == YES
+    || [[NSUserDefaults standardUserDefaults]
     boolForKey: @"NSPortIsMessagePort"])
     {
       return [NSMessagePortNameServer sharedInstance];