diff --git a/frappe/core/doctype/user_permission/user_permission.py b/frappe/core/doctype/user_permission/user_permission.py
index bd13968ba5..5ad65075e1 100644
--- a/frappe/core/doctype/user_permission/user_permission.py
+++ b/frappe/core/doctype/user_permission/user_permission.py
@@ -9,6 +9,16 @@ from frappe.permissions import (get_valid_perms, update_permission_property)
 from frappe import _
 
 class UserPermission(Document):
+	def validate(self):
+		duplicate_exists = frappe.db.get_all(self.doctype, filters={
+			'allow': self.allow,
+			'for_value': self.for_value,
+			'user': self.user,
+			'name': ['!=', self.name]
+		}, limit=1)
+		if duplicate_exists:
+			frappe.msgprint(_("User permission already exists"), raise_exception=True)
+
 	def on_update(self):
 		frappe.cache().delete_value('user_permissions')
 		frappe.publish_realtime('update_user_permissions')