diff --git a/currency_rate_date_check/__init__.py b/currency_rate_date_check/__init__.py
index 972d7471c..6c8792266 100644
--- a/currency_rate_date_check/__init__.py
+++ b/currency_rate_date_check/__init__.py
@@ -20,6 +20,6 @@
 #
 ##############################################################################
 
-import company
-import currency_rate_date_check
+from . import company
+from . import currency_rate_date_check
 
diff --git a/currency_rate_date_check/company.py b/currency_rate_date_check/company.py
index 24b9f6872..19cfe421a 100644
--- a/currency_rate_date_check/company.py
+++ b/currency_rate_date_check/company.py
@@ -20,26 +20,23 @@
 #
 ##############################################################################
 
-from openerp.osv import osv, fields
+from openerp.osv import orm, fields
 
-class res_company(osv.Model):
+class res_company(orm.Model):
     _inherit = 'res.company'
 
     _columns = {
-        'currency_rate_max_delta': fields.integer('Max Time Delta in Days for Currency Rates', help="This is the maximum interval in days between the date associated with the amount to convert and the date of the nearest currency rate available in OpenERP."),
+        'currency_rate_max_delta': fields.integer(
+            'Max Time Delta in Days for Currency Rates',
+            help="This is the maximum interval in days between the date associated with the amount to convert and the date of the nearest currency rate available in OpenERP."),
     }
 
     _defaults = {
         'currency_rate_max_delta': 7,
     }
 
-    def _check_currency_rate_max_delta(self, cr, uid, ids):
-        for company in self.read(cr, uid, ids, ['currency_rate_max_delta']):
-            if company['currency_rate_max_delta'] < 0:
-                return False
-        return True
-
-    _constraints = [
-        (_check_currency_rate_max_delta, "The value must be positive or 0", ['currency_rate_max_delta']),
-    ]
-
+    _sql_constraints = [
+        ('currency_rate_max_delta_positive',
+         'CHECK (currency_rate_max_delta >= 0)',
+         "The value of the field 'Max Time Delta in Days for Currency Rates' must be positive or 0."),
+        ]
diff --git a/currency_rate_date_check/currency_rate_date_check.py b/currency_rate_date_check/currency_rate_date_check.py
index 41207bbd3..535304403 100644
--- a/currency_rate_date_check/currency_rate_date_check.py
+++ b/currency_rate_date_check/currency_rate_date_check.py
@@ -20,7 +20,7 @@
 #
 ##############################################################################
 
-from openerp.osv import osv, fields
+from openerp.osv import fields, orm
 from datetime import datetime, timedelta
 from openerp.tools.translate import _
 
@@ -41,13 +41,14 @@ from openerp.tools.translate import _
 # => that's the solution I implement in the code below
 
 
-class res_currency(osv.Model):
+class res_currency(orm.Model):
     _inherit = 'res.currency'
 
     def _current_rate_computation(self, cr, uid, ids, name, arg, raise_on_no_rate, context=None):
+        if context is None: context = {}
         # We only do the check if there is an explicit date in the context and
         # there is no specific currency_rate_type_id
-        if context and context.get('date') and not context.get('currency_rate_type_id') and not context.get('disable_rate_date_check'):
+        if context.get('date') and not context.get('currency_rate_type_id') and not context.get('disable_rate_date_check'):
             for currency_id in ids:
                 # We could get the company from the currency, but it's not a
                 # 'required' field, so we should probably continue to get it from
@@ -61,7 +62,6 @@ class res_currency(osv.Model):
                     # now we do the real work !
                     date = context.get('date', datetime.today().strftime('%Y-%m-%d'))
                     date_datetime = datetime.strptime(date, '%Y-%m-%d')
-                    #print "date =", date
                     rate_obj = self.pool['res.currency.rate']
                     selected_rate = rate_obj.search(cr, uid, [
                         ('currency_id', '=', currency_id),
@@ -74,11 +74,9 @@ class res_currency(osv.Model):
                     rate_date = rate_obj.read(cr, uid, selected_rate[0], ['name'], context=context)['name']
                     rate_date_datetime = datetime.strptime(rate_date, '%Y-%m-%d')
                     max_delta = user.company_id.currency_rate_max_delta
-                    #print "max_delta=", max_delta
-                    #print "rate_date=", rate_date
                     if (date_datetime - rate_date_datetime).days > max_delta:
                         currency_name = self.read(cr, uid, currency_id, ['name'], context=context)['name']
-                        raise osv.except_osv(_('Error'), _('You are requesting a rate conversion on %s for currency %s but the nearest rate before that date is dated %s and the maximum currency rate time delta for your company is %s days') % (date, currency_name, rate_date, max_delta))
+                        raise orm.except_orm(_('Error'), _('You are requesting a rate conversion on %s for currency %s but the nearest rate before that date is dated %s and the maximum currency rate time delta for your company is %s days') % (date, currency_name, rate_date, max_delta))
         # Now we call the regular function from the "base" module
         return super(res_currency, self)._current_rate_computation(cr, uid, ids, name, arg, raise_on_no_rate, context=context)
 
diff --git a/currency_rate_date_check/i18n/currency_rate_date_check.po b/currency_rate_date_check/i18n/currency_rate_date_check.pot
similarity index 100%
rename from currency_rate_date_check/i18n/currency_rate_date_check.po
rename to currency_rate_date_check/i18n/currency_rate_date_check.pot