diff --git a/include/of_def.hpp b/include/of_def.hpp
index 49b0bcb..5813f7f 100644
--- a/include/of_def.hpp
+++ b/include/of_def.hpp
@@ -6,6 +6,12 @@
 #ifdef UNICODE_OFSTR
 using ofString = std::wstring;
 #define ofT(text) L##text
+#ifndef UNICODE
+#define UNICODE
+#endif
+#ifndef _UNICODE
+#define _UNICODE
+#endif
 #else
 using ofString = std::string;
 #define ofT(text) text