diff --git a/inc/wndproc.h b/inc/wndproc.h
index 43a1e8e..4d36cb3 100644
--- a/inc/wndproc.h
+++ b/inc/wndproc.h
@@ -16,6 +16,10 @@
 #define CNC_DDRAW_SET_FULLSCREEN 1
 #define CNC_DDRAW_SET_WINDOWED 2
 
+#ifndef WM_UNICHAR
+#define WM_UNICHAR 0x0109
+#endif
+
 LRESULT CALLBACK fake_WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
 
 #endif