diff --git a/themis/fields/interfaces.py b/themis/fields/interfaces.py
index bf73073..d2b146c 100644
--- a/themis/fields/interfaces.py
+++ b/themis/fields/interfaces.py
@@ -6,6 +6,10 @@ from z3c.form.interfaces import IWidget, IOrderedSelectWidget, ITextWidget
 from z3c.relationfield.interfaces import IRelation, IRelationList
 from plone.formwidget.autocomplete.interfaces import IAutocompleteWidget
 
+from zope.i18nmessageid import MessageFactory
+
+_ = MessageFactory(u'themis.fields')
+
 class ICommission(IField):
     '''Field containing a unicode string without newlines that is a commission.'''
 
diff --git a/themis/fields/widgets.py b/themis/fields/widgets.py
index 070803b..389e1c1 100644
--- a/themis/fields/widgets.py
+++ b/themis/fields/widgets.py
@@ -56,6 +56,8 @@ from z3c.form.browser.text import TextWidget
 from z3c.form.browser.radio import RadioWidget
 from plone.formwidget.contenttree.widget import ContentTreeWidget, MultiContentTreeWidget
 
+from interfaces import _
+
 @adapter(ICommission, IFormLayer)
 @implementer(IFieldWidget)
 def CommissionFieldWidget(field, request):