Onchange does not work for select helper

Rails
1

The select helper for fields_for does not properly handle settings for
onchange.

In other words, x.select fails to add any onchange options, but
x.text_field does

e.g.
<%= c.text_field :carrier, :size=>“30”, :onchange => “return
limitslist();” %>
correctly yields

but
<%= c.select :cvg_desc, %w{ GL AL EL zz }, :onchange => “return
limitslist();” %>
yields

Is this a known bug?

Thanks for any help