diff --git a/lib/puppet/parser/functions/concat.rb b/lib/puppet/parser/functions/concat.rb
index 6c8638222..0d35b07eb 100644
--- a/lib/puppet/parser/functions/concat.rb
+++ b/lib/puppet/parser/functions/concat.rb
@@ -28,11 +28,7 @@ module Puppet::Parser::Functions
       raise(Puppet::ParseError, 'concat(): Requires array to work with')
     end
 
-    if b.is_a?(Array)
-      result = a.concat(b)
-    else
-      result = a << b
-    end
+    result = a + Array(b)
 
     return result
   end