diff --git a/include/athena/Dir.hpp b/include/athena/Dir.hpp
index bbd4549..8ad8186 100644
--- a/include/athena/Dir.hpp
+++ b/include/athena/Dir.hpp
@@ -3,6 +3,7 @@
 
 #include "athena/FileInfo.hpp"
 #include <cstdio>
+#include <vector>
 
 #if _WIN32
 typedef int mode_t;
diff --git a/include/athena/Global.hpp b/include/athena/Global.hpp
index 14da238..18bd991 100644
--- a/include/athena/Global.hpp
+++ b/include/athena/Global.hpp
@@ -3,7 +3,6 @@
 
 #include <iostream>
 #include "athena/Types.hpp"
-#include "athena/Utility.hpp"
 
 #ifdef _MSC_VER
 #pragma warning(disable : 4996)
diff --git a/include/athena/IStreamReader.hpp b/include/athena/IStreamReader.hpp
index 92cf45a..c7247a5 100644
--- a/include/athena/IStreamReader.hpp
+++ b/include/athena/IStreamReader.hpp
@@ -4,6 +4,7 @@
 #include <memory>
 #include <functional>
 #include "utf8proc.h"
+#include "Utility.hpp"
 #include "IStream.hpp"
 
 namespace athena::io
diff --git a/include/athena/IStreamWriter.hpp b/include/athena/IStreamWriter.hpp
index 2fdce5a..60e6893 100644
--- a/include/athena/IStreamWriter.hpp
+++ b/include/athena/IStreamWriter.hpp
@@ -3,7 +3,9 @@
 
 #include "utf8proc.h"
 #include "IStream.hpp"
+#include "Utility.hpp"
 #include <memory>
+#include <vector>
 
 namespace athena::io
 {
diff --git a/include/athena/Utility.hpp b/include/athena/Utility.hpp
index eed3b9b..b260def 100644
--- a/include/athena/Utility.hpp
+++ b/include/athena/Utility.hpp
@@ -13,6 +13,8 @@ namespace athena::utility
 {
 inline bool isEmpty(atInt8* buf, atUint32 size) {return !memcmp(buf, buf + 1, size - 1);}
 constexpr bool isSystemBigEndian() {return __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__;}
+inline constexpr ::athena::Endian SystemEndian = isSystemBigEndian() ? Big : Little;
+inline constexpr ::athena::Endian NotSystemEndian = isSystemBigEndian() ? Little : Big;
 
 inline atInt16  swap16(atInt16 val)
 {
diff --git a/src/athena/Dir.cpp b/src/athena/Dir.cpp
index 7dba45a..74b0389 100644
--- a/src/athena/Dir.cpp
+++ b/src/athena/Dir.cpp
@@ -4,6 +4,7 @@
 #include <limits.h>
 #define __STDC_FORMAT_MACROS
 #include <cinttypes>
+#include "athena/Utility.hpp"
 
 #ifndef _WIN32
 #include <dirent.h>
diff --git a/src/athena/Global.cpp b/src/athena/Global.cpp
index 92fcb83..3a37cd8 100644
--- a/src/athena/Global.cpp
+++ b/src/athena/Global.cpp
@@ -1,4 +1,5 @@
 #include "athena/Global.hpp"
+#include "athena/Utility.hpp"
 #include <cstdio>
 #include <cstdarg>
 #include <cstdlib>