diff --git a/l10n_us_mt_hr_payroll/__manifest__.py b/l10n_us_mt_hr_payroll/__manifest__.py
index f19ac5e2..64883a44 100755
--- a/l10n_us_mt_hr_payroll/__manifest__.py
+++ b/l10n_us_mt_hr_payroll/__manifest__.py
@@ -4,7 +4,7 @@
     'license': 'AGPL-3',
     'category': 'Localization',
     'depends': ['l10n_us_hr_payroll'],
-    'version': '11.0.2019.0.0',
+    'version': '12.0.2019.0.0',
     'description': """
 USA::Montana Payroll Rules.
 ===========================
diff --git a/l10n_us_mt_hr_payroll/data/rules.xml b/l10n_us_mt_hr_payroll/data/rules.xml
index a1292185..37f39c47 100755
--- a/l10n_us_mt_hr_payroll/data/rules.xml
+++ b/l10n_us_mt_hr_payroll/data/rules.xml
@@ -12,7 +12,7 @@
         <field name="amount_select">code</field>
         <field name="amount_python_compute">
 ###
-year = int(payslip.dict.date_to[:4])
+year = payslip.dict.date_to.year
 rate = payslip.dict.get_rate('US_MT_UNEMP')
 ytd = payslip.sum('WAGE_US_MT_UNEMP', str(year) + '-01-01', str(year+1) + '-01-01')
 ytd += contract.external_wages
@@ -56,7 +56,7 @@ if result_rate == 0.0:
         <field name="condition_python">result = not contract.mt_mw4_exempt</field>
         <field name="amount_select">code</field>
         <field name="amount_python_compute">
-year = int(payslip.dict.date_to[:4])
+year = payslip.dict.date_to.year
 G = categories.GROSS
 N = contract.mt_mw4_exemptions
 additional = contract.mt_mw4_additional_withholding