Index: arch/amd64/src/userspace.c
===================================================================
--- arch/amd64/src/userspace.c	(revision b49f4ae38f84dc067e59e7ac1aaff428876a1c60)
+++ arch/amd64/src/userspace.c	(revision 909c6e38dc1bfcf7fcff02cc4a0c1552685c9084)
@@ -58,5 +58,5 @@
 			  "pushq %%rsi;"
 			  "iretq;"
-			  : : "i" (gdtselector(UDATA_DES) | PL_USER), "i" (USTACK_ADDRESS+(THREAD_STACK_SIZE-1)), "r" (pri), "i" (gdtselector(UTEXT_DES) | PL_USER), "i" (UTEXT_ADDRESS));
+			  : : "i" (gdtselector(UDATA_DES) | PL_USER), "i" (USTACK_ADDRESS+THREAD_STACK_SIZE), "r" (pri), "i" (gdtselector(UTEXT_DES) | PL_USER), "i" (UTEXT_ADDRESS));
 	
 	/* Unreachable */