diff --git a/test/unit_tests/utilities/test_utilities.hpp b/test/unit_tests/utilities/test_utilities.hpp
index e624fefda2..cc603b046c 100644
--- a/test/unit_tests/utilities/test_utilities.hpp
+++ b/test/unit_tests/utilities/test_utilities.hpp
@@ -17,6 +17,7 @@
 #include <algorithm>
 #include <iostream>
 #include <vector>
+#include <string>
 
 // Check function return flag
 int check_flag(const int flag, const std::string funcname)