diff --git a/ChangeLog b/ChangeLog
index 53d9340ea3..43074d25e2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Dec 13 11:38:12 2015  Akinori MUSHA  <knu@iDaemons.org>
+
+	* lib/shellwords.rb: Turn on frozen-string-literal after fixing
+	  shellsplit.
+
 Sun Dec 13 10:44:44 2015  Martin Duerst  <duerst@it.aoyama.ac.jp>
 
 	* KNOWNBUGS.rb: Fixed typo, made more explicit [ci skip]
diff --git a/lib/shellwords.rb b/lib/shellwords.rb
index ccc1c31060..d02d3b06d5 100644
--- a/lib/shellwords.rb
+++ b/lib/shellwords.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: false
+# frozen-string-literal: true
 ##
 # == Manipulates strings like the UNIX Bourne shell
 #
@@ -70,14 +70,14 @@ module Shellwords
   #   argv #=> ["here", "are", "two words"]
   def shellsplit(line)
     words = []
-    field = ''
+    field = String.new
     line.scan(/\G\s*(?>([^\s\\\'\"]+)|'([^\']*)'|"((?:[^\"\\]|\\.)*)"|(\\.?)|(\S))(\s|\z)?/m) do
       |word, sq, dq, esc, garbage, sep|
       raise ArgumentError, "Unmatched double quote: #{line.inspect}" if garbage
       field << (word || sq || (dq || esc).gsub(/\\(.)/, '\\1'))
       if sep
         words << field
-        field = ''
+        field = String.new
       end
     end
     words