--- a/modules/stdlib/lib/puppet/parser/functions/shuffle.rb	Sat Mar 14 20:07:04 2015 +0000
+++ b/modules/stdlib/lib/puppet/parser/functions/shuffle.rb	Sat Mar 14 20:09:45 2015 +0000
@@ -12,9 +12,8 @@
       "given (#{arguments.size} for 1)") if arguments.size < 1
 
     value = arguments[0]
-    klass = value.class
 
-    unless [Array, String].include?(klass)
+    unless value.is_a?(Array) || value.is_a?(String)
       raise(Puppet::ParseError, 'shuffle(): Requires either ' +
         'array or string to work with')
     end