diff --git a/erpnext/patches/v11_0/create_salary_structure_assignments.py b/erpnext/patches/v11_0/create_salary_structure_assignments.py
index 24874f6..8648e15 100644
--- a/erpnext/patches/v11_0/create_salary_structure_assignments.py
+++ b/erpnext/patches/v11_0/create_salary_structure_assignments.py
@@ -3,18 +3,19 @@
 
 from __future__ import unicode_literals
 import frappe
+from datetime import datetime
 
 def execute():
 	frappe.reload_doc("hr", "doctype", "salary_structure_assignment")
 	for d in frappe.db.sql("""
 		select sse.*, ss.company from `tabSalary Structure Employee` sse, `tabSalary Structure` ss
-		where ss.name = sse.parent""", as_dict=1):
+		where ss.name = sse.parent AND sse.employee in (select name from `tabEmployee` where ifNull(status, '') != 'Left')""", as_dict=1):
 		s = frappe.new_doc("Salary Structure Assignment")
 		s.employee = d.employee
 		s.employee_name = d.employee_name
 		s.salary_structure = d.parent
 		s.from_date = d.from_date
-		s.to_date = d.to_date
+		s.to_date = d.to_date if isinstance(d.to_date, datetime) else None
 		s.base = d.base
 		s.variable = d.variable
 		s.company = d.company