diff --git a/wcs/sql.py b/wcs/sql.py
index 90b759984..63f2c71d4 100644
--- a/wcs/sql.py
+++ b/wcs/sql.py
@@ -466,7 +466,7 @@ def do_formdef_tables(formdef, conn=None, cur=None, rebuild_views=False, rebuild
                                         table_name,
                                         '%s_display' % get_field_id(field)))
         if field.store_structured_value:
-            needed_fields.add('f%s_structured' % field.id)
+            needed_fields.add('%s_structured' % get_field_id(field))
             if '%s_structured' % get_field_id(field) not in existing_fields:
                 cur.execute('''ALTER TABLE %s ADD COLUMN %s bytea''' % (
                                         table_name,