diff --git a/functions b/functions
index d9bf9f1..37c6ce8 100644
--- a/functions
+++ b/functions
@@ -10,9 +10,7 @@ prepare_environment() {
   export GEM_BIN_DIR=$GEM_HOME/bin
   ruby <<EOF
 cmd = 'gem install bundler --no-document --verbose --bindir=${GEM_BIN_DIR}'
-if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.3.0') then
-  cmd += ' -v 1.17.3'
-end
+cmd += ' -v 2.2.11'
 system(cmd)
 EOF