1 files changed, 1 insertions, 0 deletions
diff --git a/diff.h b/diff.h
index e9ccb38c26..fe5c287a70 100644
--- a/diff.h
+++ b/diff.h
@@ -180,6 +180,7 @@ struct diff_options {
 	pathchange_fn_t pathchange;
 	change_fn_t change;
 	add_remove_fn_t add_remove;
+	void *change_fn_data;
 	diff_format_fn_t format_callback;
 	void *format_callback_data;
 	diff_prefix_fn_t output_prefix;