diff --git a/product/ERP5/Document/AdoptSolver.py b/product/ERP5/Document/AdoptSolver.py
index 76a3a6d7570eb393847f1b6feb9f13dec346be71..0871e58e63df4d3de72eeb4b149a9bf9a88c5974 100644
--- a/product/ERP5/Document/AdoptSolver.py
+++ b/product/ERP5/Document/AdoptSolver.py
@@ -30,7 +30,7 @@
 import zope.interface
 from AccessControl import ClassSecurityInfo
 from Products.CMFCore.utils import getToolByName
-from Products.ERP5Type import Permissions, PropertySheet
+from Products.ERP5Type import Permissions, PropertySheet, interfaces
 from Products.ERP5Type.XMLObject import XMLObject
 
 class AdoptSolver(XMLObject):
diff --git a/product/ERP5/Document/SolverDecision.py b/product/ERP5/Document/SolverDecision.py
index 287608163960dac1f7c9a579eb04d88e621080fe..8701a8ef0953c4703d5e32271740fd0af03f8341 100644
--- a/product/ERP5/Document/SolverDecision.py
+++ b/product/ERP5/Document/SolverDecision.py
@@ -30,7 +30,7 @@
 import zope.interface
 from AccessControl import ClassSecurityInfo
 from Products.CMFCore.utils import getToolByName
-from Products.ERP5Type import Permissions, PropertySheet
+from Products.ERP5Type import Permissions, PropertySheet, interfaces
 from Products.ERP5Type.XMLObject import XMLObject
 
 class SolverDecision(XMLObject):