diff --git a/gfx/common/win32_common.h b/gfx/common/win32_common.h
index 76ff1cd5fa..4b0e88054c 100644
--- a/gfx/common/win32_common.h
+++ b/gfx/common/win32_common.h
@@ -39,7 +39,7 @@ extern bool g_resized;
 extern bool g_quit;
 extern HWND g_hwnd;
 
-LRESULT win32_handle_keyboard_event(HWND hwnd, UINT message,
+extern "C" LRESULT win32_handle_keyboard_event(HWND hwnd, UINT message,
       WPARAM wparam, LPARAM lparam);
 
 LRESULT win32_menu_loop(HWND handle, WPARAM wparam);