diff --git a/frappe/email/doctype/notification/notification.py b/frappe/email/doctype/notification/notification.py
index 6b4ee92043..77979f9735 100644
--- a/frappe/email/doctype/notification/notification.py
+++ b/frappe/email/doctype/notification/notification.py
@@ -435,8 +435,8 @@ def get_context(doc):
 def get_assignees(doc):
 	assignees = []
 	assignees = frappe.get_all('ToDo', filters={'status': 'Open', 'reference_name': doc.name,
-		'reference_type': doc.doctype}, fields=['owner'])
+		'reference_type': doc.doctype}, fields=['allocated_to'])
 
-	recipients = [d.owner for d in assignees]
+	recipients = [d.allocated_to for d in assignees]
 
 	return recipients
diff --git a/frappe/model/document.py b/frappe/model/document.py
index 4312378995..e519ab257b 100644
--- a/frappe/model/document.py
+++ b/frappe/model/document.py
@@ -1347,15 +1347,15 @@ class Document(BaseDocument):
 			), frappe.exceptions.InvalidDates)
 
 	def get_assigned_users(self):
-		assignments = frappe.get_all('ToDo',
+		assigned_users = frappe.get_all('ToDo',
 			fields=['allocated_to'],
 			filters={
 				'reference_type': self.doctype,
 				'reference_name': self.name,
 				'status': ('!=', 'Cancelled'),
-			})
+			}, pluck='allocated_to')
 
-		users = set([assignment.owner for assignment in assignments])
+		users = set(assigned_users)
 		return users
 
 	def add_tag(self, tag):