diff --git a/app/helpers/welcome_helper.rb b/app/helpers/welcome_helper.rb
index d35fd8275..62cb451cc 100644
--- a/app/helpers/welcome_helper.rb
+++ b/app/helpers/welcome_helper.rb
@@ -22,6 +22,33 @@ module WelcomeHelper
   include CoursesHelper
   include ProjectsHelper
 
+  def get_timestamp(obj)
+    if obj.respond_to? :updated_on
+      :updated_on
+    elsif obj.respond_to? :updated_at
+      :updated_at
+    elsif obj.respond_to? :created_on
+      :created_on
+    elsif obj.respond_to? :created_at 
+      :created_at
+    else
+      Time.now.to_i.to_s.to_sym
+    end
+  end
+
+  def cache_key_for_project(obj)
+    timestamp = get_timestamp(obj)
+    "welcome_index_project_ul_#{obj.class}_li_#{obj.id}_#{obj.__send__ timestamp}"
+  end
+  def cache_key_for_event(obj)
+    timestamp = get_timestamp(obj)
+    "welcome_index_event_ul_#{obj.class}_li_#{obj.id}_#{obj.__send__ timestamp}"
+  end
+  def cache_key_for_topic(obj)
+    timestamp = get_timestamp(obj)
+    "welcome_index_topic_ul_#{obj.class}_li_#{obj.id}_#{obj.__send__ timestamp}"
+  end
+
   def welcome_join_in_course(project, user)
     if(user.logged? && 
         !(course_endTime_timeout? project) && 
diff --git a/app/views/welcome/index.html.erb b/app/views/welcome/index.html.erb
index 08d7d13d4..79001a3f5 100644
--- a/app/views/welcome/index.html.erb
+++ b/app/views/welcome/index.html.erb
@@ -54,7 +54,7 @@
 		<ul class="d-p-projectlist">
 			<% projects = find_miracle_project(10, 3) %>
 			<% projects.map do |project| %>
-			<% cache "welcome_index_hotProject_ul_project_#{project.id}_li" do %>
+			<% cache cache_key_for_project(project) do %>
 			<li style="position:relative;height:6em;" class='<%= cycle("odd", "even") %>'>
 				<div style="float: left;">
 					<%= image_tag(get_project_avatar(project), :class => "avatar-4") %>
@@ -88,7 +88,7 @@
 			<div class="user-message-box-list" style="margin-top: 10px;">
 				<%activities = find_all_activities%>
 			<% activities.each do |event| %>
-				<% cache "welcome_index_userActivity_ul_event_#{event.class}_#{event.id}_li" do %>
+				<% cache cache_key_for_event(event) do %>
 			<li style="display: block;height:60px; padding-bottom: 4px;">
 				<div class="inner-right" style="float: left; height: 100%; ">
 					<%= image_tag url_to_avatar(event.event_author), :class => "avatar-3" %>
@@ -119,7 +119,7 @@
 		<div class="welcome-box-list-new memo_activity">
 			<% topics = find_new_forum_topics(7) %>
 		<% topics.includes(:forum, :last_reply, :author).each do |topic|%>
-			<% cache "welcome_index_memosActivity_ul_topic_#{topic.id}_li" do %>
+			<% cache cache_key_for_topic(topic) do %>
 			<li class="message-brief-intro">
 				<div class='memo_title text_nowrap'>
 					<%= link_to '['+topic.forum.name + ']',forum_path(topic.forum),:class => 'memo_Bar_title' %><%= link_to topic.subject.truncate(30, omission: '...'), topic.event_url,title: topic.subject %>