diff --git a/ChangeLog b/ChangeLog
index 6d8b3dcda..abd04a8d2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Thu Jun 17 12:00:00 1999  Richard Frith-Macdonald <richard@brainstorm.co.uk>
+
+	* Tools/gdnc.m: Only use OpenStep NSNotificationCenter methods.
+	* Source/NSConnection.m: ditto
+	* Source/NSDistributedNotificationCenter.m: ditto
+	* Source/NSPort.m: ditto
+	* Source/NSPortNameServer.m: ditto
+	* Source/NSSerializer.m: ditto
+
 Mon Jun 14 10:20:00 1999  Richard Frith-Macdonald <richard@brainstorm.co.uk>
 
 	* Source/NSConcreteValue.m: Update for MacOS-X and for GC
diff --git a/Source/NSConnection.m b/Source/NSConnection.m
index 0ea48dea4..ec9eb5715 100644
--- a/Source/NSConnection.m
+++ b/Source/NSConnection.m
@@ -466,7 +466,7 @@ static int messages_received_count;
   /*
    *	Don't need notifications any more - so remove self as observer.
    */
-  [NSNotificationCenter removeObserver: self];
+  [[NSNotificationCenter defaultCenter] removeObserver: self];
 
   /*
    *	We can't be the ancestor of anything if we are invalid.
@@ -511,8 +511,9 @@ static int messages_received_count;
   {
     NSAutoreleasePool	*arp = [NSAutoreleasePool new];
 
-    [NSNotificationCenter postNotificationName: NSConnectionDidDieNotification
-					object: self];
+    [[NSNotificationCenter defaultCenter]
+      postNotificationName: NSConnectionDidDieNotification
+		    object: self];
     [arp release];
   }
 }
@@ -1056,7 +1057,7 @@ static int messages_received_count;
   NSHashInsert(connection_table, (void*)newConn);
   [connection_table_gate unlock];
 
-  [NSNotificationCenter
+  [[NSNotificationCenter defaultCenter]
     postNotificationName: NSConnectionDidInitializeNotification
 		  object: newConn];
 
diff --git a/Source/NSDistributedNotificationCenter.m b/Source/NSDistributedNotificationCenter.m
index 93e761412..b22325bad 100644
--- a/Source/NSDistributedNotificationCenter.m
+++ b/Source/NSDistributedNotificationCenter.m
@@ -325,11 +325,11 @@ static NSDistributedNotificationCenter	*defCenter = nil;
 	  /*
 	   *	Ask to be told if the copnnection goes away.
 	   */
-	  [NSNotificationCenter
-                    addObserver: self
-		       selector: @selector(_invalidated:)
-			   name: NSConnectionDidDieNotification
-			 object: c];
+	  [[NSNotificationCenter defaultCenter]
+	    addObserver: self
+	       selector: @selector(_invalidated:)
+		   name: NSConnectionDidDieNotification
+		 object: c];
 	  [remote registerClient: (id<GDNCClient>)self];
 	}
       else
@@ -376,9 +376,10 @@ NSLog(@"Connection to GDNC server established.\n");
   /*
    *	Tidy up now that the connection has gone away.
    */
-  [NSNotificationCenter removeObserver: self
-				  name: NSConnectionDidDieNotification
-				object: connection];
+  [[NSNotificationCenter defaultCenter]
+    removeObserver: self
+	      name: NSConnectionDidDieNotification
+	    object: connection];
   NSAssert(connection == [remote connectionForProxy],
 		 NSInternalInconsistencyException);
   [remote release];
diff --git a/Source/NSPort.m b/Source/NSPort.m
index 8c027b3d7..ef8630602 100644
--- a/Source/NSPort.m
+++ b/Source/NSPort.m
@@ -88,8 +88,9 @@ NSString *NSPortTimeoutException
 {
   [[NSPortNameServer defaultPortNameServer] removePort: self];
   is_valid = NO;
-  [NSNotificationCenter postNotificationName: NSPortDidBecomeInvalidNotification
-				      object: self];
+  [[NSNotificationCenter defaultCenter]
+    postNotificationName: NSPortDidBecomeInvalidNotification
+		  object: self];
 }
 
 - (BOOL) isValid
diff --git a/Source/NSPortNameServer.m b/Source/NSPortNameServer.m
index 92c8366a5..a02a604b0 100644
--- a/Source/NSPortNameServer.m
+++ b/Source/NSPortNameServer.m
@@ -687,15 +687,17 @@ static NSPortNameServer	*defaultServer = nil;
 {
   if (handle)
     {
-      [NSNotificationCenter removeObserver: self
-				name: GSFileHandleConnectCompletionNotification
-			      object: handle];
-      [NSNotificationCenter removeObserver: self
-				name: NSFileHandleReadCompletionNotification
-			      object: handle];
-      [NSNotificationCenter removeObserver: self
-				name: GSFileHandleWriteCompletionNotification
-			      object: handle];
+      NSNotificationCenter	*nc = [NSNotificationCenter defaultCenter];
+
+      [nc removeObserver: self
+		    name: GSFileHandleConnectCompletionNotification
+		  object: handle];
+      [nc removeObserver: self
+		    name: NSFileHandleReadCompletionNotification
+		  object: handle];
+      [nc removeObserver: self
+		    name: GSFileHandleWriteCompletionNotification
+		  object: handle];
       [handle closeFile];
       [handle release];
       handle = nil;
@@ -721,9 +723,10 @@ static NSPortNameServer	*defaultServer = nil;
        *	stop watching for connection completion.
        */ 
       expecting = 0;
-      [NSNotificationCenter removeObserver: self
-				name: GSFileHandleConnectCompletionNotification
-			      object: handle];
+      [[NSNotificationCenter defaultCenter]
+	removeObserver: self
+		  name: GSFileHandleConnectCompletionNotification
+		object: handle];
     }
 }
 
diff --git a/Tools/gdnc.m b/Tools/gdnc.m
index 3c0410ac5..fa65417df 100644
--- a/Tools/gdnc.m
+++ b/Tools/gdnc.m
@@ -174,15 +174,16 @@
 
 - (void) dealloc
 {
+  NSNotificationCenter	*nc = [NSNotificationCenter defaultCenter];
   NSMapEnumerator	enumerator;
   NSConnection		*connection;
   NSMapTable		*clients;
 
   if (conn)
     {
-      [NSNotificationCenter removeObserver: self
-				      name: NSConnectionDidDieNotification
-				    object: conn];
+      [nc removeObserver: self
+		    name: NSConnectionDidDieNotification
+		  object: conn];
       [conn release];
       conn = nil;
     }
@@ -195,9 +196,9 @@
   while (NSNextMapEnumeratorPair(&enumerator,
 		(void**)&connection, (void**)&clients) == YES)
     {
-      [NSNotificationCenter removeObserver: self
-				      name: NSConnectionDidDieNotification
-				    object: connection];
+      [nc removeObserver: self
+		    name: NSConnectionDidDieNotification
+		  object: connection];
       [self removeObserversForClients: clients];
       NSFreeMapTable(clients);
     }
@@ -236,10 +237,11 @@
    *	Get notifications for new connections and connection losses.
    */
   [conn setDelegate: self];
-  [NSNotificationCenter addObserver: self
-			   selector: @selector(connectionBecameInvalid:)
-			       name: NSConnectionDidDieNotification
-			     object: conn];
+  [[NSNotificationCenter defaultCenter]
+    addObserver: self
+       selector: @selector(connectionBecameInvalid:)
+	   name: NSConnectionDidDieNotification
+	 object: conn];
   return self;
 }
 
@@ -341,10 +343,11 @@
 {
   NSMapTable	*table;
 
-  [NSNotificationCenter addObserver: self
-			   selector: @selector(connectionBecameInvalid:)
-			       name: NSConnectionDidDieNotification
-			     object: newConn];
+  [[NSNotificationCenter defaultCenter]
+    addObserver: self
+       selector: @selector(connectionBecameInvalid:)
+	   name: NSConnectionDidDieNotification
+	 object: newConn];
   [newConn setDelegate: self];
   /*
    *	Create a new map table entry for this connection with a value that
@@ -361,9 +364,10 @@
 {
   id connection = [notification object];
 
-  [NSNotificationCenter removeObserver: self
-				  name: NSConnectionDidDieNotification
-				object: connection];
+  [[NSNotificationCenter defaultCenter]
+    removeObserver: self
+	      name: NSConnectionDidDieNotification
+	    object: connection];
 
   if (connection == conn)
     {