diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 0db104a15d0..5a99a5d3550 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -152,7 +152,6 @@ class ApplicationController < ActionController::Base
                 :tag_request,
                 :check_if_login_required,
                 :log_requesting_user,
-                :reset_i18n_fallbacks,
                 :check_session_lifetime,
                 :stop_if_feeds_disabled,
                 :set_cache_buster,
@@ -224,14 +223,6 @@ class ApplicationController < ActionController::Base
     string.gsub(/[^0-9a-zA-Z@._\-"'!?=\/ ]{1}/, "#")
   end
 
-  def reset_i18n_fallbacks
-    fallbacks = [I18n.default_locale] + Redmine::I18n.valid_languages.map(&:to_sym)
-    return if I18n.fallbacks.defaults == fallbacks
-
-    I18n.fallbacks = nil
-    I18n.fallbacks.defaults = fallbacks
-  end
-
   def set_localization
     # 1. Use completely authenticated user
     # 2. Use user with some authenticated stages not completed.
diff --git a/config/initializers/i18n.rb b/config/initializers/i18n.rb
index e0e5a345e0a..696514bf902 100644
--- a/config/initializers/i18n.rb
+++ b/config/initializers/i18n.rb
@@ -33,15 +33,13 @@
 require "open_project/translations/pluralization_backend"
 I18n::Backend::Simple.include OpenProject::Translations::PluralizationBackend
 
-# Adds fallback to default locale for untranslated strings
+# Adds fallback to default locale for untranslated strings. Useful for instance
+# during development when adding new strings and using another locale than
+# English. For production, that's less useful as files downloaded from Crowdin
+# already contain fallback English translations.
+#
+# Also we can't completly remove the fallback mechanism: we still need the it to
+# get translated versions of email header and footer as they are supplied by the
+# admins and may not be provided for all configured languages. (See
+# `Setting#localized_emails_header` and `Setting#localized_emails_footer`.)
 I18n::Backend::Simple.include I18n::Backend::Fallbacks
-
-Rails.application.reloader.to_prepare do
-  # As we enabled +config.i18n.fallbacks+, Rails will fall back
-  # to the default locale.
-  # When other locales are available, fall back to them.
-  if Setting.table_exists? # don't want to prevent migrations
-    defaults = Set.new(I18n.fallbacks.defaults + Redmine::I18n.valid_languages.map(&:to_sym))
-    I18n.fallbacks.defaults = defaults
-  end
-end