diff --git a/headers/private/kernel/kernel.h b/headers/private/kernel/kernel.h
index 7c056bd2d9..cd1932ae93 100644
--- a/headers/private/kernel/kernel.h
+++ b/headers/private/kernel/kernel.h
@@ -1,12 +1,17 @@
-/* 
-** Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
-** Distributed under the terms of the NewOS License.
-*/
+/*
+ * Copyright 2002-2004, Axel Dörfler, axeld@pinc-software.de.
+ * Distributed under the terms of the MIT License.
+ *
+ * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
+ * Distributed under the terms of the NewOS License.
+ */
 #ifndef _KERNEL_KERNEL_H
 #define _KERNEL_KERNEL_H
 
 
 #include <arch_kernel.h>
+#include <arch_config.h>
+
 
 /* Passed in buffers from user-space shouldn't point into the kernel */
 #define IS_USER_ADDRESS(x) \
@@ -16,13 +21,17 @@
 	((addr_t)(x) >= KERNEL_BASE && (addr_t)(x) <= KERNEL_TOP)
 
 /** Size of the kernel stack */
-#define KSTACK_SIZE	(B_PAGE_SIZE * 2)
+#ifndef DEBUG_KERNEL_STACKS
+#	define KERNEL_STACK_SIZE		(B_PAGE_SIZE * 2)	// 8 kB
+#else
+#	define KERNEL_STACK_SIZE		(B_PAGE_SIZE * 3)	// 8 kB + one guard page
+#endif
+#define KERNEL_STACK_GUARD_PAGES	1
 
 /** Size of the stack given to teams in user space */
-#define MAIN_THREAD_STACK_SIZE	(16 * B_PAGE_SIZE)	// 64 kB
-	// BeOS: (16 * 1024 * 1024)	// 16 MB
-#define STACK_SIZE				(16 * B_PAGE_SIZE)
-	// BeOS: (256 * 1024)		// 256 kB
+#define USER_MAIN_THREAD_STACK_SIZE	(16 * 1024 * 1024)	// 16 MB
+#define USER_STACK_SIZE				(256 * 1024)		// 256 kB
+#define USER_STACK_GUARD_PAGES		4					// 16 kB
 
 /** Size of the environmental variables space for a process */
 #define ENV_SIZE	(B_PAGE_SIZE * 8)