diff --git a/app/controllers/application_controller/authenticates.rb b/app/controllers/application_controller/authenticates.rb
index b4087434b..af92d076e 100644
--- a/app/controllers/application_controller/authenticates.rb
+++ b/app/controllers/application_controller/authenticates.rb
@@ -27,7 +27,8 @@ module ApplicationController::Authenticates
 
     # check if basic_auth fallback is possible
     if auth_param[:basic_auth_promt] && !user
-      return request_http_basic_authentication
+      request_http_basic_authentication
+      return false
     end
 
     # return auth not ok
diff --git a/spec/requests/calendar_subscriptions_spec.rb b/spec/requests/calendar_subscriptions_spec.rb
new file mode 100644
index 000000000..5869e164b
--- /dev/null
+++ b/spec/requests/calendar_subscriptions_spec.rb
@@ -0,0 +1,11 @@
+require 'rails_helper'
+
+RSpec.describe 'iCal endpoints', type: :request do
+  context 'with no existing session' do
+    it 'gives HTTP Basic auth prompt (#3064)' do
+      get '/ical/tickets'
+
+      expect(response.body).to eq("HTTP Basic: Access denied.\n")
+    end
+  end
+end