diff --git a/builtin/commit.c b/builtin/commit.c
index e1af9b1..9679a99 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -272,7 +272,7 @@
 			item->util = item; /* better a valid pointer than a fake one */
 	}
 
-	return report_path_error(m, pattern, prefix ? strlen(prefix) : 0);
+	return report_path_error(m, pattern, prefix);
 }
 
 static void add_remove_files(struct string_list *list)