// Create search engine instance and set options
$search = $this->buildSearchEngine( $params );
$search->setFeatureData( 'rewrite', (bool)$params['enablerewrites'] );
+ $search->setFeatureData( 'interwiki', (bool)$interwiki );
$query = $search->transformSearchTerm( $query );
$query = $search->replacePrefixes( $query );