Solr/Dismax with dynamic fields

Question

I just added some wildcard dynamic fields to my solr schema:

<dynamicField name="*_s" type="string" indexed="true" stored="true"/>

Then I add a document with field name like asdfasdf_s

If I do a query that brings up this document, I see that asdfasdf_s is stored in the results with the value I set.

However, if I search by the value in that dynamic field, I get no results. I am using the dismax query parser.