diff --git a/sys/i386/include/stack.h b/sys/i386/include/stack.h
index 773aca1c66d9..3bc1e1a3997f 100644
--- a/sys/i386/include/stack.h
+++ b/sys/i386/include/stack.h
@@ -21,7 +21,7 @@ static __inline bool
 kstack_contains(struct thread *td, vm_offset_t va, size_t len)
 {
 	return (va >= td->td_kstack && va + len >= va &&
-	    va + len <= td->td_kstack + td->td_kstack_pages * PAGE_SIZE);
+	    va + len <= (vm_offset_t)get_pcb_td(td));
 }
 
 #endif	/* _SYS_PROC_H_ */