diff --git a/internal/engine.hpp b/internal/engine.hpp
index 7b54b55..842523c 100644
--- a/internal/engine.hpp
+++ b/internal/engine.hpp
@@ -15,6 +15,7 @@
 #include <algorithm>
 #include <iostream>
 #include <codecvt>
+#include <map>
 #include "lang.hpp"
 #include "parameter.hpp"
 #include "thread.hpp"