diff --git a/mm/bootmem.c b/mm/bootmem.c
index e8a55a3c9febae80fab4627bc8f0846f4326c56a..9fedb27c6451418035fdf26300fbdf8d9c7fc6c9 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -53,7 +53,7 @@ early_param("bootmem_debug", bootmem_debug_setup);
 
 static unsigned long __init bootmap_bytes(unsigned long pages)
 {
-	unsigned long bytes = DIV_ROUND_UP(pages, 8);
+	unsigned long bytes = DIV_ROUND_UP(pages, BITS_PER_BYTE);
 
 	return ALIGN(bytes, sizeof(long));
 }