diff --git a/src/rectpack2D/finders_interface.h b/src/rectpack2D/finders_interface.h
index 9e85568..e3436f3 100644
--- a/src/rectpack2D/finders_interface.h
+++ b/src/rectpack2D/finders_interface.h
@@ -128,6 +128,7 @@ namespace rectpack2D {
 
 		return find_best_packing_impl<empty_spaces_type, order_type>(
 			[ith_order](auto callback) {
+				constexpr auto count_orders = 1 + sizeof...(Comparators);
 				for (std::size_t i = 0; i < count_orders; ++i) {
 					callback(ith_order(i));
 				}