diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index 2373b39a132b5eacaf0341fcfb351e99c912c1a7..22db04550f6a03ff92580e801b860cc4ed757ebc 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -305,7 +305,7 @@ static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info,
 
 	spin_lock(&fs_info->reada_lock);
 	ret = radix_tree_insert(&dev->reada_zones,
-				(unsigned long)zone->end >> PAGE_CACHE_SHIFT,
+				(unsigned long)(zone->end >> PAGE_CACHE_SHIFT),
 				zone);
 	spin_unlock(&fs_info->reada_lock);