diff --git a/app/jobs/scheduled/check_out_of_date_themes.rb b/app/jobs/scheduled/check_out_of_date_themes.rb
new file mode 100644
index 00000000000..8bd992f6e89
--- /dev/null
+++ b/app/jobs/scheduled/check_out_of_date_themes.rb
@@ -0,0 +1,16 @@
+module Jobs
+  class CheckOutOfDateThemes < Jobs::Scheduled
+    every 1.day
+
+    def execute(args)
+      target_themes = RemoteTheme
+        .joins("JOIN themes ON themes.remote_theme_id = remote_themes.id")
+        .where.not(remote_url: "")
+
+      target_themes.each do |remote|
+        remote.update_remote_version
+        remote.save!
+      end
+    end
+  end
+end
diff --git a/app/models/admin_dashboard_data.rb b/app/models/admin_dashboard_data.rb
index b64e82dfaca..fffdd0e0360 100644
--- a/app/models/admin_dashboard_data.rb
+++ b/app/models/admin_dashboard_data.rb
@@ -101,7 +101,8 @@ class AdminDashboardData
                       :github_config_check, :s3_config_check, :image_magick_check,
                       :failing_emails_check,
                       :subfolder_ends_in_slash_check,
-                      :pop3_polling_configuration, :email_polling_errored_recently
+                      :pop3_polling_configuration, :email_polling_errored_recently,
+                      :out_of_date_themes
 
     add_problem_check do
       sidekiq_check || queue_size_check
@@ -247,4 +248,16 @@ class AdminDashboardData
     I18n.t('dashboard.force_https_warning') unless SiteSetting.force_https
   end
 
+  def out_of_date_themes
+    old_themes = RemoteTheme.out_of_date_themes
+    return unless old_themes.present?
+
+    html = old_themes.map do |name, id|
+      "<li><a href=\"/admin/customize/themes/#{id}\">#{CGI.escapeHTML(name)}</a></li>"
+    end.join("\n")
+
+    message = I18n.t("dashboard.out_of_date_themes")
+    message += "<ul>#{html}</ul>"
+    message
+  end
 end
diff --git a/app/models/remote_theme.rb b/app/models/remote_theme.rb
index f817a090a7a..578711a4c59 100644
--- a/app/models/remote_theme.rb
+++ b/app/models/remote_theme.rb
@@ -56,11 +56,18 @@ class RemoteTheme < ActiveRecord::Base
     end
   end
 
+  def self.out_of_date_themes
+    self.joins("JOIN themes ON themes.remote_theme_id = remote_themes.id")
+      .where.not(remote_url: "")
+      .where("commits_behind > 0 OR remote_version <> local_version")
+      .pluck("themes.name", "themes.id")
+  end
+
   def update_remote_version
     importer = ThemeStore::GitImporter.new(remote_url, private_key: private_key)
     importer.import!
     self.updated_at = Time.zone.now
-    self.remote_version, self.commits_behind = importer.commits_since(remote_version)
+    self.remote_version, self.commits_behind = importer.commits_since(local_version)
   end
 
   def update_from_remote(importer = nil, skip_update: false)
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index ecd2ec798cd..cc10f8c9cb8 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -1097,6 +1097,7 @@ en:
     poll_pop3_timeout: "Connection to the POP3 server is timing out. Incoming email could not be retrieved. Please check your <a href='/admin/site_settings/category/email'>POP3 settings</a> and service provider."
     poll_pop3_auth_error: "Connection to the POP3 server is failing with an authentication error. Please check your <a href='/admin/site_settings/category/email'>POP3 settings</a>."
     force_https_warning: "Your website is using SSL. But `<a href='/admin/site_settings/category/all_results?filter=force_https'>force_https</a>` is not yet enabled in your site settings."
+    out_of_date_themes: "Updates are available for the following themes:"
 
   site_settings:
     censored_words: "Words that will be automatically replaced with &#9632;&#9632;&#9632;&#9632;"
diff --git a/spec/models/admin_dashboard_data_spec.rb b/spec/models/admin_dashboard_data_spec.rb
index f65de862fd1..1a96b1fe9e1 100644
--- a/spec/models/admin_dashboard_data_spec.rb
+++ b/spec/models/admin_dashboard_data_spec.rb
@@ -336,4 +336,19 @@ describe AdminDashboardData do
     end
   end
 
+  describe '#out_of_date_themes' do
+    let(:remote) { RemoteTheme.create!(remote_url: "https://github.com/org/testtheme") }
+    let!(:theme) { Theme.create!(remote_theme_id: remote.id, name: "Test< Theme", user_id: -1) }
+
+    it "outputs correctly formatted html" do
+      remote.update!(local_version: "old version", remote_version: "new version", commits_behind: 2)
+      dashboard_data = described_class.new
+      expect(dashboard_data.out_of_date_themes).to eq(
+        I18n.t("dashboard.out_of_date_themes") + "<ul><li><a href=\"/admin/customize/themes/#{theme.id}\">Test&lt; Theme</a></li></ul>"
+      )
+
+      remote.update!(local_version: "new version", commits_behind: 0)
+      expect(dashboard_data.out_of_date_themes).to eq(nil)
+    end
+  end
 end
diff --git a/spec/models/remote_theme_spec.rb b/spec/models/remote_theme_spec.rb
index 31f772b94ec..202e170b0a3 100644
--- a/spec/models/remote_theme_spec.rb
+++ b/spec/models/remote_theme_spec.rb
@@ -151,4 +151,17 @@ describe RemoteTheme do
       expect(scheme_count).to eq(1)
     end
   end
+
+  context ".out_of_date_themes" do
+    let(:remote) { RemoteTheme.create!(remote_url: "https://github.com/org/testtheme") }
+    let!(:theme) { Theme.create!(remote_theme_id: remote.id, name: "Test Theme", user_id: -1) }
+
+    it "finds out of date themes" do
+      remote.update!(local_version: "old version", remote_version: "new version", commits_behind: 2)
+      expect(described_class.out_of_date_themes).to eq([[theme.name, theme.id]])
+
+      remote.update!(local_version: "new version", commits_behind: 0)
+      expect(described_class.out_of_date_themes).to eq([])
+    end
+  end
 end