diff --git a/include/ehs/Str.h b/include/ehs/Str.h
index b56485c..367d9c6 100644
--- a/include/ehs/Str.h
+++ b/include/ehs/Str.h
@@ -1892,9 +1892,9 @@ namespace ehs
         }
 	};
 
-	typedef Str<Char_32, UInt_64> Str_32;
-	typedef Str<Char_16, UInt_64> Str_16;
-	typedef Str<Char_8, UInt_64> Str_8;
+	EHS_LIB_IO typedef Str<Char_32, UInt_64> Str_32;
+	EHS_LIB_IO typedef Str<Char_16, UInt_64> Str_16;
+	EHS_LIB_IO typedef Str<Char_8, UInt_64> Str_8;
 }
 
 template<typename T = ehs::Char_8, typename N = ehs::UInt_64>
diff --git a/include/ehs/system/OS.h b/include/ehs/system/OS.h
index fe5db29..d5bc370 100644
--- a/include/ehs/system/OS.h
+++ b/include/ehs/system/OS.h
@@ -1,11 +1,19 @@
 #pragma once
 
 #if defined(_WIN32) || defined(_WIN64)
-#define EHS_OS_WINDOWS
+	#define EHS_OS_WINDOWS
     #define EHS_FILE __FILE__
     #define EHS_FUNC __FUNCTION__
     #define EHS_LINE __LINE__
 
+	#if defined(EHS_EXPORT)
+		#define EHS_LIB_IO __declspec(dllexport)
+	#elif defined(EHS_IMPORT)
+		#define EHS_LIB_IO __declspec(dllimport)
+	#else
+		#define EHS_LIB_IO
+	#endif
+
     #ifndef NOMINMAX
         #define NOMINMAX
     #endif
@@ -22,6 +30,7 @@
 	#define EHS_FILE __FILE__
 	#define EHS_FUNC __FUNCTION__
 	#define EHS_LINE __LINE__
+	#define EHS_LIB_IO
 
-typedef int Handle;
+	typedef int Handle;
 #endif
\ No newline at end of file