diff --git a/src/Helper.hpp b/src/Helper.hpp
index 1acf6f6..0465ae0 100644
--- a/src/Helper.hpp
+++ b/src/Helper.hpp
@@ -14,7 +14,7 @@
 #include <algorithm>
 #include <sstream>
 #include <iomanip>
-
+#include <cstddef>
 /* Public defines -----------------------------------------------------------*/
 
 /* Public class -------------------------------------------------------------*/