Index: kernel/arch/amd64/include/mm/as.h
===================================================================
--- kernel/arch/amd64/include/mm/as.h	(revision 2438fa6a9b8e68cb9f47b431a63f2c238edf5691)
+++ kernel/arch/amd64/include/mm/as.h	(revision 712c4bac34d2d8ac8d7e35e7e48ff1c293c0ffb8)
@@ -43,9 +43,6 @@
 #define KERNEL_ADDRESS_SPACE_START_ARCH  UINT64_C(0xffff800000000000)
 #define KERNEL_ADDRESS_SPACE_END_ARCH    UINT64_C(0xffffffffffffffff)
-
-#define USER_ADDRESS_SPACE_START_ARCH  UINT64_C(0x0000000000000000)
-#define USER_ADDRESS_SPACE_END_ARCH    UINT64_C(0x00007fffffffffff)
-
-#define USTACK_ADDRESS_ARCH  (USER_ADDRESS_SPACE_END_ARCH - (PAGE_SIZE - 1))
+#define USER_ADDRESS_SPACE_START_ARCH    UINT64_C(0x0000000000000000)
+#define USER_ADDRESS_SPACE_END_ARCH      UINT64_C(0x00007fffffffffff)
 
 #define as_constructor_arch(as, flags)  (as != as)
Index: kernel/arch/amd64/src/proc/scheduler.c
===================================================================
--- kernel/arch/amd64/src/proc/scheduler.c	(revision 2438fa6a9b8e68cb9f47b431a63f2c238edf5691)
+++ kernel/arch/amd64/src/proc/scheduler.c	(revision 712c4bac34d2d8ac8d7e35e7e48ff1c293c0ffb8)
@@ -56,5 +56,5 @@
 {
 	CPU->arch.tss->rsp0 =
-	    (uintptr_t) &THREAD->kstack[THREAD_STACK_SIZE];
+	    (uintptr_t) &THREAD->kstack[STACK_SIZE];
 	
 	/*
Index: kernel/arch/amd64/src/userspace.c
===================================================================
--- kernel/arch/amd64/src/userspace.c	(revision 2438fa6a9b8e68cb9f47b431a63f2c238edf5691)
+++ kernel/arch/amd64/src/userspace.c	(revision 712c4bac34d2d8ac8d7e35e7e48ff1c293c0ffb8)
@@ -66,5 +66,5 @@
 		"iretq\n"
 		:: [udata_des] "i" (GDT_SELECTOR(UDATA_DES) | PL_USER),
-		   [stack_size] "r" (kernel_uarg->uspace_stack + THREAD_STACK_SIZE),
+		   [stack_size] "r" (kernel_uarg->uspace_stack + STACK_SIZE),
 		   [ipl] "r" (ipl),
 		   [utext_des] "i" (GDT_SELECTOR(UTEXT_DES) | PL_USER),