diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e79177ac2dc2..c9187d95a54b 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1118,11 +1118,11 @@ static void blkcg_fill_root_iostats(void)
 				cpu_dkstats->ios[STAT_DISCARD];
 			// convert sectors to bytes
 			tmp.bytes[BLKG_IOSTAT_READ] +=
-				cpu_dkstats->sectors[STAT_READ] << 9;
+				(u64)cpu_dkstats->sectors[STAT_READ] << 9;
 			tmp.bytes[BLKG_IOSTAT_WRITE] +=
-				cpu_dkstats->sectors[STAT_WRITE] << 9;
+				(u64)cpu_dkstats->sectors[STAT_WRITE] << 9;
 			tmp.bytes[BLKG_IOSTAT_DISCARD] +=
-				cpu_dkstats->sectors[STAT_DISCARD] << 9;
+				(u64)cpu_dkstats->sectors[STAT_DISCARD] << 9;
 		}
 
 		flags = u64_stats_update_begin_irqsave(&blkg->iostat.sync);