diff --git a/wcs_olap/feeder.py b/wcs_olap/feeder.py
index 8c4cd7d..abf47ce 100644
--- a/wcs_olap/feeder.py
+++ b/wcs_olap/feeder.py
@@ -774,8 +774,10 @@ class WcsFormdefFeeder(object):
                     # map items to sql id
                     if field.items or field.options:
                         v = self.items_mappings[field.varname].get(raw)
+                    elif raw:
+                        v = self.get_item_id(field, raw)
                     else:
-                        v = raw and self.get_item_id(field, raw)
+                        v = None
                 elif field.type in ('string', 'bool'):
                     v = raw