diff --git a/base_phone/models/__init__.py b/base_phone/models/__init__.py
index e4ebd1e..0252a7d 100644
--- a/base_phone/models/__init__.py
+++ b/base_phone/models/__init__.py
@@ -4,3 +4,4 @@ from . import base
 from . import res_company
 from . import res_partner
 from . import phone_common
+from . import ir_fields_converter
diff --git a/base_phone/models/ir_fields_converter.py b/base_phone/models/ir_fields_converter.py
new file mode 100644
index 0000000..0a350ad
--- /dev/null
+++ b/base_phone/models/ir_fields_converter.py
@@ -0,0 +1,17 @@
+# -*- coding: utf-8 -*-
+# © 2016 Akretion (Alexis de Lattre <alexis.delattre@akretion.com>)
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from odoo import models, api
+
+
+class IrFieldsConverter(models.AbstractModel):
+    _inherit = 'ir.fields.converter'
+
+    @api.model
+    def _str_to_phone(self, model, field, value):
+        return super(IrFieldsConverter, self)._str_to_char(model, field, value)
+
+    @api.model
+    def _str_to_fax(self, model, field, value):
+        return super(IrFieldsConverter, self)._str_to_char(model, field, value)