diff --git a/modules/purchase/purchase.py b/modules/purchase/purchase.py
index 0b2edae..bd7c51b 100755
--- a/modules/purchase/purchase.py
+++ b/modules/purchase/purchase.py
@@ -1021,15 +1021,14 @@ class Purchase(
         pool = Pool()
         Invoice = pool.get('account.invoice')
 
-        Invoice.save(invoices.values())
-        for inv in invoices:
-            #check if forex
-            forex_rate = inv.get_forex()
-            if forex_rate:
-                inv.selection_rate = 'forex'
-                Invoice.save([inv])
+        Invoice.save(invoices.values())    
                 
         for purchase, invoice in invoices.items():
+            #check if forex
+            forex_rate = invoice.get_forex()
+            if forex_rate:
+                invoice.selection_rate = 'forex'
+                Invoice.save([invoice])
             purchase.copy_resources_to(invoice)
             if len(invoices)==1:
                 if prepayment: