How to search by title field only? How do I change this template code to only return results from the title field of an entry?

The search result page url would look like this: /search-results?q=joe+blogs

{% set query = craft.request.getParam('q') %}
{% set entries = craft.entries.section('not thisSection').search(query).order('score') %}


Thanks for any help.
This seems to work:

{% set entries = craft.entries.section('not lakeDetails').search('title:' ~ query).order('score') %}