diff --git a/include/form.h b/include/form.h
index a822c5626..301493ee1 100755
--- a/include/form.h
+++ b/include/form.h
@@ -833,6 +833,7 @@ public:
   //          (chiama <mf TForm_item::get_special_item>)
   const char* get_special_value(const char* s) const 
   { return get_special_item(s, 1); }
+  void TForm_item::set_special_value(const char* s, const char* val);
   // @cmember Ritorna il tipo dello special corrispondente al nome <p s>
   //          (chiama <mf TForm_item::get_special_item>)  
   const char* get_special_type (const char* s) const