diff --git a/product/ERP5/PropertySheet/TradeOrderLine.py b/product/ERP5/PropertySheet/TradeOrderLine.py
index 607df23a782f5a1573378ebdb1afc50f9ca117d2..30f51d2386335a150a53bb303f42b97cb794e7e5 100644
--- a/product/ERP5/PropertySheet/TradeOrderLine.py
+++ b/product/ERP5/PropertySheet/TradeOrderLine.py
@@ -33,7 +33,7 @@ class TradeOrderLine:
   _constraints = (
     { 'id'            : 'resource',
       'description'   : 'Resource must be defined',
-      'type'          : 'CategoryMembershipArity',
+      'type'          : 'CategoryAcquiredMembershipArity',
       'min_arity'     : '1',
       'max_arity'     : '1',
       'portal_type'   : ( ),