diff --git a/headers/private/kernel/arch/m68k/arch_kernel.h b/headers/private/kernel/arch/m68k/arch_kernel.h
index d212052810..85e9168d33 100644
--- a/headers/private/kernel/arch/m68k/arch_kernel.h
+++ b/headers/private/kernel/arch/m68k/arch_kernel.h
@@ -25,7 +25,8 @@
 #define USER_SIZE     (0x80000000 - (0x10000 + 0x100000))
 #define USER_TOP      (USER_BASE + USER_SIZE)
 
-#define USER_STACK_REGION 0x70000000
-#define USER_STACK_REGION_SIZE (USER_BASE + (USER_SIZE - USER_STACK_REGION))
+#define KERNEL_USER_DATA_BASE  0x6fff0000
+#define USER_STACK_REGION              0x70000000
+#define USER_STACK_REGION_SIZE (USER_TOP - USER_STACK_REGION)
 
 #endif	/* _KERNEL_ARCH_M68K_KERNEL_H */
diff --git a/headers/private/kernel/arch/ppc/arch_kernel.h b/headers/private/kernel/arch/ppc/arch_kernel.h
index 862a54118f..3886034f11 100644
--- a/headers/private/kernel/arch/ppc/arch_kernel.h
+++ b/headers/private/kernel/arch/ppc/arch_kernel.h
@@ -25,7 +25,8 @@
 #define USER_SIZE     (0x80000000 - (0x10000 + 0x100000))
 #define USER_TOP      (USER_BASE + USER_SIZE)
 
-#define USER_STACK_REGION 0x70000000
-#define USER_STACK_REGION_SIZE (USER_BASE + (USER_SIZE - USER_STACK_REGION))
+#define KERNEL_USER_DATA_BASE  0x6fff0000
+#define USER_STACK_REGION              0x70000000
+#define USER_STACK_REGION_SIZE (USER_TOP - USER_STACK_REGION)
 
 #endif	/* _KERNEL_ARCH_PPC_KERNEL_H */