diff --git a/grub-core/disk/luks2.c b/grub-core/disk/luks2.c
index 8d2457557..8c1156dd0 100644
--- a/grub-core/disk/luks2.c
+++ b/grub-core/disk/luks2.c
@@ -631,7 +631,7 @@ luks2_recover_key (grub_disk_t source,
       crypt->log_sector_size = sizeof (unsigned int) * 8
 		- __builtin_clz ((unsigned int) segment.sector_size) - 1;
       if (grub_strcmp (segment.size, "dynamic") == 0)
-	crypt->total_sectors = (grub_disk_native_sectors (source) >> (crypt->log_sector_size - source->log_sector_size))
+	crypt->total_sectors = (grub_disk_native_sectors (source) >> (crypt->log_sector_size - GRUB_DISK_SECTOR_BITS))
 			       - crypt->offset_sectors;
       else
 	crypt->total_sectors = grub_strtoull (segment.size, NULL, 10) >> crypt->log_sector_size;