diff --git a/config/application.rb b/config/application.rb
index 796aa85e113ff97e6453fbe1d388a9a637d19a6b..5804d8fd27b6992aa9b26f2ed4a39d2b71a3bd7a 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -69,6 +69,12 @@ module Gitlab
     # config.i18n.default_locale = :de
     config.i18n.enforce_available_locales = false
 
+    # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
+    # the I18n.default_locale when a translation can not be found).
+    # We have to explicitly set default locale since 1.1.0 - see:
+    # https://github.com/svenfuchs/i18n/pull/415
+    config.i18n.fallbacks = [:en]
+
     # Translation for AR attrs is not working well for POROs like WikiPage
     config.gettext_i18n_rails.use_for_active_record_attributes = false
 
diff --git a/config/environments/production.rb b/config/environments/production.rb
index 71195164e7a021b8f60a1b2a820beb46fe7b38db..49a4e873093a066eaf103b7b3ba9adc2af0b3c95 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -65,10 +65,6 @@ Rails.application.configure do
   # Enable threaded mode
   # config.threadsafe! unless $rails_rake_task
 
-  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
-  # the I18n.default_locale when a translation can not be found)
-  config.i18n.fallbacks = true
-
   # Send deprecation notices to registered listeners
   config.active_support.deprecation = :notify