diff --git a/tests/helpers_for_testing.hpp b/tests/helpers_for_testing.hpp
index a5daa58..148ef8c 100644
--- a/tests/helpers_for_testing.hpp
+++ b/tests/helpers_for_testing.hpp
@@ -8,6 +8,7 @@
 #include <fstream>
 #include <iostream>
 #include <random>
+#include <array>
 
 namespace HelpersForTests {