diff --git a/frappe/core/doctype/user/user.py b/frappe/core/doctype/user/user.py
index 0462de8643..a4d13a57e0 100644
--- a/frappe/core/doctype/user/user.py
+++ b/frappe/core/doctype/user/user.py
@@ -56,6 +56,7 @@ class User(Document):
 
 	def after_insert(self):
 		create_notification_settings(self.name)
+		frappe.cache().delete_key('users_for_mentions')
 
 	def validate(self):
 		self.check_demo()
@@ -129,6 +130,9 @@ class User(Document):
 		if self.time_zone:
 			frappe.defaults.set_default("time_zone", self.time_zone, self.name)
 
+		if self.has_value_changed('allow_in_mentions') or self.has_value_changed('user_type'):
+			frappe.cache().delete_key('users_for_mentions')
+
 	def has_website_permission(self, ptype, user, verbose=False):
 		"""Returns true if current user is the session user"""
 		return self.name == frappe.session.user
@@ -389,6 +393,9 @@ class User(Document):
 		# delete notification settings
 		frappe.delete_doc("Notification Settings", self.name, ignore_permissions=True)
 
+		if self.get('allow_in_mentions'):
+			frappe.cache().delete_key('users_for_mentions')
+
 
 	def before_rename(self, old_name, new_name, merge=False):
 		self.check_demo()
diff --git a/frappe/core/doctype/user_group/user_group.py b/frappe/core/doctype/user_group/user_group.py
index 64bffa06d0..b1d0fede4c 100644
--- a/frappe/core/doctype/user_group/user_group.py
+++ b/frappe/core/doctype/user_group/user_group.py
@@ -9,7 +9,7 @@ import frappe
 
 class UserGroup(Document):
 	def after_insert(self):
-		frappe.publish_realtime('user_group_added', self.name)
+		frappe.cache().delete_key('user_groups')
 
 	def on_trash(self):
-		frappe.publish_realtime('user_group_deleted', self.name)
+		frappe.cache().delete_key('user_groups')