diff --git a/utils/misc.py b/utils/misc.py
index 9050bf8..e59704f 100644
--- a/utils/misc.py
+++ b/utils/misc.py
@@ -26,3 +26,8 @@ class Extension(object):
 
     def parse_odoo_datetime(self, datetime: str):
         return dt.datetime.strptime(datetime, DEFAULT_SERVER_DATETIME_FORMAT)
+
+    def to_fixed(self, number, digit=2):
+        if isinstance(number, str) and number.isdigit():
+            number = float(number)
+        return format(number, ".{digit}f".format(digit=digit))
diff --git a/wizard/res_partner_contract_wizard.py b/wizard/res_partner_contract_wizard.py
index ba94e6d..479ad69 100644
--- a/wizard/res_partner_contract_wizard.py
+++ b/wizard/res_partner_contract_wizard.py
@@ -5,9 +5,11 @@ from odoo.exceptions import ValidationError
 
 from ..utils import MODULE_NAME
 from ..utils.docxtpl import get_document_from_values_stream
+from ..utils.misc import Extension
 
 
-class ContractWizard(models.TransientModel):
+
+class ContractWizard(models.TransientModel, Extension):
     _name = "res.partner.contract.wizard"
 
     def _default_target(self):