diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 801c08b..6f80bed 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -24,9 +24,9 @@
 static int bdi_debug_stats_show(struct seq_file *m, void *v)
 {
 	struct backing_dev_info *bdi = m->private;
-	long background_thresh;
-	long dirty_thresh;
-	long bdi_thresh;
+	unsigned long background_thresh;
+	unsigned long dirty_thresh;
+	unsigned long bdi_thresh;
 
 	get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi);