diff --git a/app/server/ruby/core.rb b/app/server/ruby/core.rb
index a456703e05..65e5d2a78b 100755
--- a/app/server/ruby/core.rb
+++ b/app/server/ruby/core.rb
@@ -691,7 +691,7 @@ def length
       end
 
       def map(&block)
-        @vec.map(&block)
+        self.class.new(@vec.map(&block))
       end
 
       def max(n=nil, &block)