diff --git a/Gemfile b/Gemfile
index 1aadbb9..60c65b6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -23,7 +23,7 @@ source 'https://rubygems.org'
 
 require 'rails'
 
-if Gem::Version.new(Rails.gem_version) >= Gem::Version.new('5.0.0')
-  gem 'acts_as_list'
-  gem 'activemodel-serializers-xml'
-end
\ No newline at end of file
+# In order to the plugin in Redmine < 4 (Rails < 5), comment out the following lines
+# I don't know how to check Redmine or better Rails version here :-(
+gem 'acts_as_list'
+gem 'activemodel-serializers-xml'