diff --git a/lib/aos/paging.c b/lib/aos/paging.c
index 6a4fce2..837c997 100644
--- a/lib/aos/paging.c
+++ b/lib/aos/paging.c
@@ -487,7 +487,7 @@ errval_t paging_map_fixed_attr(struct paging_state *st, lvaddr_t vaddr,
     assert(bytes % BASE_PAGE_SIZE == 0);
     lvaddr_t end_vaddr = vaddr + bytes;
     assert(VADDR_OFFSET <= vaddr && vaddr < end_vaddr &&
-           end_vaddr <= VADDR_OFFSET + PTABLE_ENTRIES * PTABLE_ENTRIES * BASE_PAGE_SIZE);
+           end_vaddr <= VADDR_OFFSET + PTABLE_ENTRIES * PTABLE_ENTRIES *PTABLE_ENTRIES * PTABLE_ENTRIES * BASE_PAGE_SIZE);
            
     // consistentcy checks
     assert(st != NULL);