diff --git a/diff.c b/diff.c
index 377ec1ea4c..0b61cf7c7f 100644
--- a/diff.c
+++ b/diff.c
@@ -1445,7 +1445,7 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
 	 */
 
 	if (options->stat_width == -1)
-		width = term_columns();
+		width = term_columns() - options->output_prefix_length;
 	else
 		width = options->stat_width ? options->stat_width : 80;