diff --git a/plugin/disk_format/disk_format40.c b/plugin/disk_format/disk_format40.c
index 41d7bbc..d9a0d49 100644
--- a/plugin/disk_format/disk_format40.c
+++ b/plugin/disk_format/disk_format40.c
@@ -298,9 +298,11 @@ static int try_init_format40(struct super_block *super,
 	if (result == REISER4_STATUS_MOUNT_WARN)
 		notice("vpf-1363", "Warning: mounting %s with errors.",
 		       super->s_id);
-	if (result == REISER4_STATUS_MOUNT_RO)
+	if (result == REISER4_STATUS_MOUNT_RO) {
 		notice("vpf-1364", "Warning: mounting %s with fatal errors,"
 		       " forcing read-only mount.", super->s_id);
+		super->s_flags |= MS_RDONLY;
+	}
 	result = reiser4_journal_replay(super);
 	if (result)
 		return result;