diff --git a/src/fp/fplib01.cpp b/src/fp/fplib01.cpp
index 42f2ac5ec..4b40a60c9 100644
--- a/src/fp/fplib01.cpp
+++ b/src/fp/fplib01.cpp
@@ -858,7 +858,7 @@ const TString& TDoc_fp::converti_prezzo(const real& prezzo) const
 	return ret;
 }
 
-void TDoc_fp::set_qta_prezzo(TPaf_record paf1800f, TRiga_documento* rdoc)
+void TDoc_fp::set_qta_prezzo(TPaf_record& paf1800f, TRiga_documento* rdoc)
 {
 	const real qta = rdoc->get(RDOC_QTA);
 	if (qta >= ZERO)
diff --git a/src/fp/fplib01.h b/src/fp/fplib01.h
index a8a11ce8b..c223d41b8 100644
--- a/src/fp/fplib01.h
+++ b/src/fp/fplib01.h
@@ -124,7 +124,7 @@ protected:
 	bool add_row_art(long& riga_art, const TString codice_tipo, const TString& codice_valore, TPaf_record& paf);
 	bool add_row_alleg(TFilename& file, long& nprogr, TPaf_record& paf);
 	const TString& converti_prezzo(const real& prezzo) const;
-	void set_qta_prezzo(TPaf_record paf1800f, TRiga_documento* rdoc);
+	void set_qta_prezzo(TPaf_record& paf1800f, TRiga_documento* rdoc);
 
 public:
 	bool doc_to_paf(TDocumentoEsteso& doc);