parse_tax_query causing Navigation Menu To Disappear

I am using the following snippet to modify a query...

function no_child_terms($query) {
    if( !is_admin())    {
  $query->tax_query->queries[0]['include_children'] = 0;
  }
}
add_action('parse_tax_query', 'no_child_terms');

This is working correctly and it is modifying the query correctly but it is causing my navigation menu to disappear. Am I using parse_tax_query correctly?