diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index c91e139..8fe9d34 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -598,7 +598,7 @@
 	spin_lock(&sb_lock);
 	list_for_each_entry(sb, &super_blocks, s_list) {
 		if (sb->s_bdi == bdi)
-			sb->s_bdi = NULL;
+			sb->s_bdi = &default_backing_dev_info;
 	}
 	spin_unlock(&sb_lock);
 }