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
diff --git a/spec/functions/concat_spec.rb b/spec/functions/concat_spec.rb
index b853b4c1a..49cb2ad7f 100755
--- a/spec/functions/concat_spec.rb
+++ b/spec/functions/concat_spec.rb
@@ -27,4 +27,9 @@
     expect(result).to(eq(['1','2','3',['4','5'],'6']))
   end
 
+  it "should leave the original array intact" do
+    array_original = ['1','2','3']
+    result = scope.function_concat([array_original,['4','5','6']])
+    array_original.should(eq(['1','2','3']))
+  end
 end