diff --git a/preprocessor.py b/preprocessor.py
index 1e113000..a0a862db 100755
--- a/preprocessor.py
+++ b/preprocessor.py
@@ -172,6 +172,9 @@ if __name__ == '__main__':
 
 #define STATIC_ASSERT(MSG) static_assert(false, MSG);
 
+#define DECLARE_STRUCT(KLASS) struct KLASS;
+#define DECLARE_CLASS(KLASS) class KLASS;
+
 
 ///////////////////////////////////////////////////////////////////////////////
     """)