diff --git a/block/genhd.c b/block/genhd.c
index c2fb3f7bdec47..40a06b934b1fd 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -829,6 +829,7 @@ static void disk_seqf_stop(struct seq_file *seqf, void *v)
 	if (iter) {
 		class_dev_iter_exit(iter);
 		kfree(iter);
+		seqf->private = NULL;
 	}
 }