diff --git a/cucumber.yml b/cucumber.yml
index c18af4e913..dec1ca02e8 100644
--- a/cucumber.yml
+++ b/cucumber.yml
@@ -2,10 +2,10 @@
 cucumber_pro_opts = ENV['ENABLE_CUCUMBER_PRO'] ? "--format Cucumber::Pro --out /dev/null" : ""
 rerun = File.file?('rerun.txt') ? IO.read('rerun.txt') : ""
 rerun_opts = rerun.to_s.strip.empty? ? "--format progress features" : "--format pretty #{rerun}"
-std_opts = "--format progress features -r features --strict #{cucumber_pro_opts}"
+std_opts = "--format progress features -r features --strict #{cucumber_pro_opts}".dup
 std_opts << " --tags ~@wip-jruby" if defined?(JRUBY_VERSION)
 
-wip_opts = "--color -r features"
+wip_opts = "--color -r features".dup
 wip_opts << " --tags @wip" if !defined?(JRUBY_VERSION)
 wip_opts << " --tags @wip,@wip-jruby" if defined?(JRUBY_VERSION)
 %>
diff --git a/lib/cucumber/term/ansicolor.rb b/lib/cucumber/term/ansicolor.rb
index 61cf49a803..c4b1c73ce6 100644
--- a/lib/cucumber/term/ansicolor.rb
+++ b/lib/cucumber/term/ansicolor.rb
@@ -56,7 +56,7 @@ def self.coloring=(val)
       ATTRIBUTES.each do |c, v|
         eval %Q{
             def #{c}(string = nil)
-              result = ''
+              result = String.new
               result << "\e[#{v}m" if Cucumber::Term::ANSIColor.coloring?
               if block_given?
                 result << yield