diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 0b994496dc0..0f948222982 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -560,4 +560,16 @@ module ApplicationHelper
       end
     end
   end
+
+  def authentication_data
+    return @authentication_data if defined?(@authentication_data)
+
+    @authentication_data = begin
+      value = cookies[:authentication_data]
+      if value
+        cookies.delete(:authentication_data, path: Discourse.base_path("/"))
+      end
+      current_user ? nil : value
+    end
+  end
 end
diff --git a/app/views/layouts/application.html.erb b/app/views/layouts/application.html.erb
index 165ece79e1e..796a7be265d 100644
--- a/app/views/layouts/application.html.erb
+++ b/app/views/layouts/application.html.erb
@@ -60,8 +60,8 @@
 
     <%= tag.meta id: 'data-discourse-setup', data: client_side_setup_data %>
 
-    <%- if !current_user && (data = cookies.delete(:authentication_data, path: Discourse.base_path("/"))) %>
-      <meta id="data-authentication" data-authentication-data="<%= data %>">
+    <%- if authentication_data %>
+      <meta id="data-authentication" data-authentication-data="<%= authentication_data %>">
     <%- end %>
   </head>
 
diff --git a/spec/requests/application_controller_spec.rb b/spec/requests/application_controller_spec.rb
index 5e82551fc2b..1ac69118a79 100644
--- a/spec/requests/application_controller_spec.rb
+++ b/spec/requests/application_controller_spec.rb
@@ -104,11 +104,21 @@ RSpec.describe ApplicationController do
     end
 
     it 'contains authentication data when cookies exist' do
-      COOKIE_DATA = "someauthenticationdata"
-      cookies['authentication_data'] = COOKIE_DATA
+      cookie_data = "someauthenticationdata"
+      cookies['authentication_data'] = cookie_data
       get '/login'
       expect(response.status).to eq(200)
-      expect(response.body).to include("data-authentication-data=\"#{COOKIE_DATA }\"")
+      expect(response.body).to include("data-authentication-data=\"#{cookie_data}\"")
+      expect(response.headers["Set-Cookie"]).to include("authentication_data=;") # Delete cookie
+    end
+
+    it 'deletes authentication data cookie even if already authenticated' do
+      sign_in(Fabricate(:user))
+      cookies['authentication_data'] = "someauthenticationdata"
+      get '/'
+      expect(response.status).to eq(200)
+      expect(response.body).not_to include("data-authentication-data=")
+      expect(response.headers["Set-Cookie"]).to include("authentication_data=;") # Delete cookie
     end
   end