diff --git a/src/userprog/process.c b/src/userprog/process.c
index 4f72dc0..fd07a07 100644
--- a/src/userprog/process.c
+++ b/src/userprog/process.c
@@ -571,7 +571,7 @@ setup_stack (void **esp)
     {
       success = install_page (((uint8_t *) PHYS_BASE) - PGSIZE, kpage, true);
       if (success)
-        *esp = PHYS_BASE - 12;
+        *esp = PHYS_BASE;
       else
         palloc_free_page (kpage);
     }