diff --git a/erpnext/setup/doctype/email_digest/email_digest.py b/erpnext/setup/doctype/email_digest/email_digest.py
index 631c0bc..eadb9b1 100644
--- a/erpnext/setup/doctype/email_digest/email_digest.py
+++ b/erpnext/setup/doctype/email_digest/email_digest.py
@@ -135,7 +135,7 @@
 		notifications = frappe.desk.notifications.get_notifications()
 
 		notifications = sorted(notifications.get("open_count_doctype", {}).items(),
-			lambda a, b: 1 if a[1] < b[1] else -1)
+			key=lambda a: a[1])
 
 		notifications = [{"key": n[0], "value": n[1],
 			"link": get_url_to_list(n[0])} for n in notifications if n[1]]