diff --git a/src/window.cpp b/src/window.cpp
index b8629c9a..ba765409 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -23,11 +23,6 @@
 
 #include "window.h"
 
-/// FIXME: dirty workaround.
-#ifdef WIN32
-# define wcwidth(x) 1
-#endif // WIN32
-
 using namespace NCurses;
 
 void NCurses::InitScreen(GNUC_UNUSED const char *window_title, bool enable_colors)
diff --git a/src/window.h b/src/window.h
index 93a1373f..4be700ad 100644
--- a/src/window.h
+++ b/src/window.h
@@ -57,6 +57,11 @@
 # define TO_WSTRING(x) (x)
 #endif
 
+// workaraund for win32
+#ifdef WIN32
+# define wcwidth(x) 1
+#endif
+
 std::string ToString(const std::wstring &);
 std::wstring ToWString(const std::string &);