diff --git a/sys/fs/ext2fs/ext2fs.h b/sys/fs/ext2fs/ext2fs.h
index 225e05892d68..361e61fa7799 100644
--- a/sys/fs/ext2fs/ext2fs.h
+++ b/sys/fs/ext2fs/ext2fs.h
@@ -281,9 +281,13 @@ struct ext2_gd {
 	uint32_t ext2bgd_i_tables;	/* inodes table block  */
 	uint16_t ext2bgd_nbfree;	/* number of free blocks */
 	uint16_t ext2bgd_nifree;	/* number of free inodes */
-	uint16_t ext2bgd_ndirs;	/* number of directories */
-	uint16_t reserved;
-	uint32_t reserved2[3];
+	uint16_t ext2bgd_ndirs;		/* number of directories */
+	uint16_t ext2bgd_flags;		/* block group flags */
+	uint32_t ext2bgd_x_bitmap;	/* snapshot exclusion bitmap loc. */
+	uint16_t ext2bgd_b_bmap_csum;	/* block bitmap checksum */
+	uint16_t ext2bgd_i_bmap_csum;	/* inode bitmap checksum */
+	uint16_t ext2bgd_i_unused;	/* unused inode count */
+	uint16_t ext2bgd_csum;		/* group descriptor checksum */
 };
 
 /* cluster summary information */