diff --git a/fs/btrfs/defrag.c b/fs/btrfs/defrag.c
index 75c87aee5de9..7010d714cfe1 100644
--- a/fs/btrfs/defrag.c
+++ b/fs/btrfs/defrag.c
@@ -811,7 +811,7 @@ static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em,
 	 * If the next extent is at its max capacity, defragging current extent
 	 * makes no sense, as the total number of extents won't change.
 	 */
-	if (next->len >= get_extent_max_capacity(fs_info, em))
+	if (next->len >= get_extent_max_capacity(fs_info, next))
 		goto out;
 	/* Skip older extent */
 	if (next->generation < newer_than)