diff --git a/invoice.odt b/invoice.odt
index e7ff20cb22..22e80bc647 100644
Binary files a/invoice.odt and b/invoice.odt differ
diff --git a/invoice.py b/invoice.py
index 61611bcc63..90e2f059cf 100644
--- a/invoice.py
+++ b/invoice.py
@@ -1344,7 +1344,8 @@ class InvoiceLine(OSV):
     def get_unit_digits(self, cursor, user, ids, name, arg, context=None):
         res = {}
         for line in self.browse(cursor, user, ids, context=context):
-            res[line.id] = line.unit.digits
+            if line.unit:
+                res[line.id] = line.unit.digits
         return res
 
     def get_amount(self, cursor, user, ids, name, arg, context=None):