diff --git a/addons/l10n_in_hr_payroll/report/report_hr_salary_employee_bymonth.py b/addons/l10n_in_hr_payroll/report/report_hr_salary_employee_bymonth.py
index cf66edccbf5..27f46d1972c 100644
--- a/addons/l10n_in_hr_payroll/report/report_hr_salary_employee_bymonth.py
+++ b/addons/l10n_in_hr_payroll/report/report_hr_salary_employee_bymonth.py
@@ -68,18 +68,18 @@ class report_hr_salary_employee_bymonth(report_sxw.rml_parse):
             self.mnths.append('None')
         return [mnth_name]
 
-    def get_salary(self, form, emp_id, emp_salary, total_mnths, category):
-        ids = []
-        category_ids = form.get('category_id', [])
-        ids.append(category_ids[0])
+    def get_salary(self, form, emp_id, emp_salary, total_mnths):
+        categories = form.get('category_id', [])
+        category_ids = []
+        category_ids.append(categories[0])
 
         self.cr.execute("select to_char(date_to,'mm-yyyy') as to_date ,sum(pl.total) \
                              from hr_payslip_line as pl \
                              left join hr_payslip as p on pl.slip_id = p.id \
                              left join hr_employee as emp on emp.id = p.employee_id \
                              left join resource_resource as r on r.id = emp.resource_id  \
-                            where p.state = 'done' and p.employee_id = %s and pl.category_id in %s \
-                            group by r.name, p.date_to,emp.id",(emp_id,tuple(ids),))
+                            where p.state = 'done' and p.employee_id = %s and pl.category_id = %s \
+                            group by r.name, p.date_to,emp.id",(emp_id,tuple(category_ids),))
         sal = self.cr.fetchall()
         salary = dict(sal)
         total = 0.0
@@ -105,7 +105,6 @@ class report_hr_salary_employee_bymonth(report_sxw.rml_parse):
         emp_salary = []
         salary_list = []
         total_mnths=['Total', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
-        category = form.get('category_id', [])
         emp_obj = self.pool.get('hr.employee')
         emp_ids = form.get('employee_ids', [])
         employees  = emp_obj.browse(self.cr, self.uid, emp_ids, context=self.context)
@@ -113,7 +112,7 @@ class report_hr_salary_employee_bymonth(report_sxw.rml_parse):
         for emp_id in employees:
             emp_salary.append(emp_id.name)
             total = 0.0
-            emp_salary, total, total_mnths = self.get_salary(form, emp_id.id, emp_salary, total_mnths, category)
+            emp_salary, total, total_mnths = self.get_salary(form, emp_id.id, emp_salary, total_mnths)
             emp_salary.append(total)
             salary_list.append(emp_salary)
             emp_salary = []