diff --git a/lib/device/dev-swap.c b/lib/device/dev-swap.c
index bf3604bb7..d1feb0c87 100644
--- a/lib/device/dev-swap.c
+++ b/lib/device/dev-swap.c
@@ -59,7 +59,7 @@ int dev_is_swap(struct device *dev, uint64_t *offset_found)
 		 */
 		if (page == 0x8000)
 			continue;
-		if (size < (page / 512))
+		if (size < (page >> SECTOR_SHIFT))
 			break;
 		if (!dev_read(dev, page - SIGNATURE_SIZE,
 			      SIGNATURE_SIZE, buf)) {