diff --git a/MtService/MtService.h b/MtService/MtService.h
index c3ba2fdb..3e375f5c 100755
--- a/MtService/MtService.h
+++ b/MtService/MtService.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <string>
 #include <thread>
 #include <unordered_map>