diff --git a/src/userprog/process.c b/src/userprog/process.c
index fdcf2c4..701078a 100644
--- a/src/userprog/process.c
+++ b/src/userprog/process.c
@@ -457,7 +457,7 @@ setup_stack (void **esp)
     {
       success = install_page (((uint8_t *) PHYS_BASE) - PGSIZE, kpage, true);
       if (success)
-        *esp = PHYS_BASE;
+        *esp = PHYS_BASE - 12;
       else
         palloc_free_page (kpage);
     }