diff --git a/spec/i18n_spec.rb b/spec/i18n_spec.rb
index 7fb59edde..e1d60e2fc 100644
--- a/spec/i18n_spec.rb
+++ b/spec/i18n_spec.rb
@@ -44,6 +44,7 @@ describe 'I18n' do
 
       I18n.enforce_available_locales = false
       I18n.locale = :zz
+      I18n.fallbacks[:zz] << I18n.default_locale
 
       expect(I18n.t("test_plural", count: 0)).to eq("No comments")
       expect(I18n.t("test_plural", count: 1)).to eq("1 comment")