diff --git a/lib/simplecov/formatter/simple_formatter.rb b/lib/simplecov/formatter/simple_formatter.rb
index cc7fa9a9..a90e7859 100644
--- a/lib/simplecov/formatter/simple_formatter.rb
+++ b/lib/simplecov/formatter/simple_formatter.rb
@@ -6,7 +6,7 @@ module Formatter
     class SimpleFormatter
       # Takes a SimpleCov::Result and generates a string out of it
       def format(result)
-        output = ""
+        output = "".dup
         result.groups.each do |name, files|
           output << "Group: #{name}\n"
           output << "=" * 40
diff --git a/lib/simplecov/version.rb b/lib/simplecov/version.rb
index 443eb9d4..bac1ee82 100644
--- a/lib/simplecov/version.rb
+++ b/lib/simplecov/version.rb
@@ -1,5 +1,5 @@
 module SimpleCov
-  version = "0.14.1"
+  version = "0.14.1".dup
 
   def version.to_a
     split(".").map(&:to_i)