diff --git a/app/assets/javascripts/discourse/mixins/ajax.js b/app/assets/javascripts/discourse/mixins/ajax.js
index cc85af1db8..c69c8ef051 100644
--- a/app/assets/javascripts/discourse/mixins/ajax.js
+++ b/app/assets/javascripts/discourse/mixins/ajax.js
@@ -1,13 +1,7 @@
 /**
   This mixin provides an 'ajax' method that can be used to perform ajax requests that
   respect Discourse paths and the run loop.
-
-  @class Discourse.Ajax
-  @extends Ember.Mixin
-  @namespace Discourse
-  @module Discourse
 **/
-
 var _trackView = false;
 
 Discourse.Ajax = Em.Mixin.create({
@@ -56,8 +50,14 @@ Discourse.Ajax = Em.Mixin.create({
         args.headers['Discourse-Track-View'] = true;
       }
 
-      args.success = function(xhr) {
-        Ember.run(null, resolve, xhr);
+      args.success = function(data, textStatus, xhr) {
+        if (xhr.getResponseHeader('Discourse-Readonly')) {
+          Ember.run(function() {
+            Discourse.Site.currentProp('isReadOnly', true);
+          });
+        }
+
+        Ember.run(null, resolve, data);
       };
 
       args.error = function(xhr, textStatus) {
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 146fe5771b..f676d276e8 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -42,6 +42,7 @@ class ApplicationController < ActionController::Base
   before_filter :preload_json
   before_filter :check_xhr
   before_filter :redirect_to_login_if_required
+  after_filter  :add_readonly_header
 
   layout :set_layout
 
@@ -53,6 +54,10 @@ class ApplicationController < ActionController::Base
     @use_crawler_layout ||= (has_escaped_fragment? || CrawlerDetection.crawler?(request.user_agent))
   end
 
+  def add_readonly_header
+    response.headers['Discourse-Readonly'] = 'true' if Discourse.readonly_mode?
+  end
+
   def slow_platform?
     request.user_agent =~ /Android/
   end
@@ -394,7 +399,7 @@ class ApplicationController < ActionController::Base
 
     def block_if_readonly_mode
       return if request.fullpath.start_with?(path "/admin/backups")
-      raise Discourse::ReadOnly.new if !request.get? && Discourse.readonly_mode?
+      raise Discourse::ReadOnly.new if !(request.get? || request.head?) && Discourse.readonly_mode?
     end
 
     def build_not_found_page(status=404, layout=false)
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 79eddd24ce..1bf579bc35 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -613,7 +613,7 @@ en:
     logout: "You were logged out."
     refresh: "Refresh"
     read_only_mode:
-      enabled: "An administrator enabled read-only mode. You can continue to browse the site but interactions may not work."
+      enabled: "Read-only mode is enabled. You can continue to browse the site but interactions may not work."
       login_disabled: "Login is disabled while the site is in read only mode."
     too_few_topics_notice: "Create at least 5 public topics and %{posts} public posts to get discussion started. New users cannot earn trust levels unless there's content for them to read. This message appears only to staff."
 
diff --git a/lib/discourse.rb b/lib/discourse.rb
index 304318ca4d..46f27f8fce 100644
--- a/lib/discourse.rb
+++ b/lib/discourse.rb
@@ -191,7 +191,7 @@ module Discourse
   end
 
   def self.readonly_mode?
-    !!$redis.get(readonly_mode_key)
+    DiscourseRedis.recently_readonly? || !!$redis.get(readonly_mode_key)
   end
 
   def self.request_refresh!
diff --git a/lib/discourse_redis.rb b/lib/discourse_redis.rb
index dd74515be4..b0a56d29ba 100644
--- a/lib/discourse_redis.rb
+++ b/lib/discourse_redis.rb
@@ -4,6 +4,19 @@
 require_dependency 'cache'
 class DiscourseRedis
 
+  def self.recently_readonly?
+    return false unless @last_read_only
+    @last_read_only > 15.seconds.ago
+  end
+
+  def self.received_readonly!
+    @last_read_only = Time.now
+  end
+
+  def self.clear_readonly!
+    @last_read_only = nil
+  end
+
   def self.raw_connection(config = nil)
     config ||= self.config
     redis_opts = {host: config['host'], port: config['port'], db: config['db']}
@@ -38,7 +51,10 @@ class DiscourseRedis
     yield
   rescue Redis::CommandError => ex
     if ex.message =~ /READONLY/
-      STDERR.puts "WARN: Redis is in a readonly state. Performed a noop"
+      unless DiscourseRedis.recently_readonly?
+        STDERR.puts "WARN: Redis is in a readonly state. Performed a noop"
+      end
+      DiscourseRedis.received_readonly!
     else
       raise ex
     end
diff --git a/spec/components/discourse_spec.rb b/spec/components/discourse_spec.rb
index 66ec12d977..09426698a9 100644
--- a/spec/components/discourse_spec.rb
+++ b/spec/components/discourse_spec.rb
@@ -107,16 +107,23 @@ describe Discourse do
 
   context "#readonly_mode?" do
 
+    after do
+      DiscourseRedis.clear_readonly!
+    end
+
+    it "is false by default" do
+      expect(Discourse.readonly_mode?).to eq(false)
+    end
+
     it "returns true when the key is present in redis" do
       $redis.expects(:get).with(Discourse.readonly_mode_key).returns("1")
       expect(Discourse.readonly_mode?).to eq(true)
     end
 
-    it "returns false when the key is not present in redis" do
-      $redis.expects(:get).with(Discourse.readonly_mode_key).returns(nil)
-      expect(Discourse.readonly_mode?).to eq(false)
+    it "returns true when DiscourseRedis is recently read only" do
+      DiscourseRedis.received_readonly!
+      expect(Discourse.readonly_mode?).to eq(true)
     end
-
   end
 
   context "#handle_exception" do
diff --git a/spec/controllers/application_controller_spec.rb b/spec/controllers/application_controller_spec.rb
index b42d1fa3a2..eb35d6caa0 100644
--- a/spec/controllers/application_controller_spec.rb
+++ b/spec/controllers/application_controller_spec.rb
@@ -107,6 +107,18 @@ describe TopicsController do
     end
   end
 
+  describe "read only header" do
+    it "returns no read only header by default" do
+      get :show, {topic_id: topic.id}
+      expect(response.headers['Discourse-Readonly']).to eq(nil)
+    end
+
+    it "returns a readonly header if the site is read only" do
+      DiscourseRedis.received_readonly!
+      get :show, {topic_id: topic.id}
+      expect(response.headers['Discourse-Readonly']).to eq('true')
+    end
+  end
 end
 
 describe 'api' do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 2f888104a2..1f650b73be 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -113,6 +113,8 @@ Spork.prefork do
       # very expensive IO operations
       SiteSetting.automatically_download_gravatars = false
 
+      DiscourseRedis.clear_readonly!
+
       I18n.locale = :en
     end