diff --git a/mozilla/xpcom/macbuild/xpcom.Prefix b/mozilla/xpcom/macbuild/xpcom.Prefix
index 507f65b847c..af1f7757b2a 100644
--- a/mozilla/xpcom/macbuild/xpcom.Prefix
+++ b/mozilla/xpcom/macbuild/xpcom.Prefix
@@ -1,8 +1,27 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+
 //
-//	JavaScript.Prefix
+//	xpcom.Prefix
 //
-// Global prefix file for the JavaScriptPPC project.
+// Global prefix file for the xpcom project.
 //
 //
 
-#include "xpcomConfig.h"
\ No newline at end of file
+#include "MacPrefix.h"
+#include "xpcomConfig.h"
diff --git a/mozilla/xpcom/macbuild/xpcomConfig.h b/mozilla/xpcom/macbuild/xpcomConfig.h
index 18071a403e3..769a7a9706b 100644
--- a/mozilla/xpcom/macbuild/xpcomConfig.h
+++ b/mozilla/xpcom/macbuild/xpcomConfig.h
@@ -1,10 +1,19 @@
-#error "Don't use me"
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
 
-#define EDITOR 1
-
-#include "NSCrossProductDefines.h"
-#include "IDE_Options.h"
-
-//#define JAVA
-
-#define MOZILLA_CLIENT 1
+/* Nothing to do here. Add xpcom-specific defines here if necessary */
diff --git a/mozilla/xpcom/macbuild/xpcomDebug.Prefix b/mozilla/xpcom/macbuild/xpcomDebug.Prefix
index 48ec0a1c4a0..dab4c95f253 100644
--- a/mozilla/xpcom/macbuild/xpcomDebug.Prefix
+++ b/mozilla/xpcom/macbuild/xpcomDebug.Prefix
@@ -1,10 +1,27 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+
 //
-//	JavaScriptDebug.Prefix
+//	xpcomDebug.Prefix
 //
-// Global prefix file for the JavaScriptPPCDebug project.
+// Global prefix file for the xpcomDebug project.
 //
 //
 
-#define DEBUG 1
-#define DEVELOPER_DEBUG 1
-#include "xpcomConfig.h"
\ No newline at end of file
+#include "MacPrefix_debug.h"
+#include "xpcomConfig.h"
diff --git a/mozilla/xpcom/macbuild/xpcomPPC.mcp b/mozilla/xpcom/macbuild/xpcomPPC.mcp
index d5445b5c407..cad52c5c73e 100644
Binary files a/mozilla/xpcom/macbuild/xpcomPPC.mcp and b/mozilla/xpcom/macbuild/xpcomPPC.mcp differ