diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index 94bb1a4bf..81792f90d 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -30,9 +30,6 @@ ActiveRecord::Migration.maintain_test_schema!
 # make sure that all migrations of linked packages are executed
 Package::Migration.linked
 
-# allow requests to Zammad webservices
-WebMock.disable_net_connect!(allow: /zammad\.com/)
-
 RSpec.configure do |config|
   # Remove this line if you're not using ActiveRecord or ActiveRecord fixtures
   config.fixture_path = "#{::Rails.root}/spec/fixtures"
diff --git a/spec/support/webmock.rb b/spec/support/webmock.rb
new file mode 100644
index 000000000..2c11259b6
--- /dev/null
+++ b/spec/support/webmock.rb
@@ -0,0 +1,12 @@
+# allow requests to:
+# - Zammad webservices
+# - Google (calendar)
+allowed_sites = lambda do |uri|
+  ['zammad.com', 'google.com'].any? do |site|
+    uri.host.include?(site)
+  end
+end
+WebMock.disable_net_connect!(
+  allow:           allowed_sites,
+  allow_localhost: true
+)