diff --git a/code/solr/Solr.php b/code/solr/Solr.php
index 98d3972..72a1305 100644
--- a/code/solr/Solr.php
+++ b/code/solr/Solr.php
@@ -1,8 +1,12 @@
 <?php
+
 namespace SilverStripe\FullTextSearch\Solr;
 
 use SilverStripe\Control\Director;
 use SilverStripe\Core\Object;
+use SilverStripe\FullTextSearch\Search\FullTextSearch;
+use SilverStripe\FullTextSearch\Solr\Services\Solr4Service;
+use SilverStripe\FullTextSearch\Solr\Services\Solr3Service;
 
 class Solr
 {
@@ -78,13 +82,13 @@ class Solr
 
         if (version_compare($version, '4', '>=')) {
             $versionDefaults = array(
-                'service' => 'Solr4Service',
+                'service' => Solr4Service::class,
                 'extraspath' => Director::baseFolder().'/fulltextsearch/conf/solr/4/extras/',
                 'templatespath' => Director::baseFolder().'/fulltextsearch/conf/solr/4/templates/',
             );
         } else {
             $versionDefaults = array(
-                'service' => 'Solr3Service',
+                'service' => Solr3Service::class,
                 'extraspath' => Director::baseFolder().'/fulltextsearch/conf/solr/3/extras/',
                 'templatespath' => Director::baseFolder().'/fulltextsearch/conf/solr/3/templates/',
             );
@@ -136,7 +140,7 @@ class Solr
 
     public static function get_indexes()
     {
-        return FullTextSearch::get_indexes('SolrIndex');
+        return FullTextSearch::get_indexes(SolrIndex::class);
     }
 
     /**
@@ -156,4 +160,4 @@ class Solr
             $included = true;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/code/solr/SolrIndex.php b/code/solr/SolrIndex.php
index 8884a4a..b9714fd 100644
--- a/code/solr/SolrIndex.php
+++ b/code/solr/SolrIndex.php
@@ -1,9 +1,20 @@
 <?php
+
 namespace SilverStripe\FullTextSearch\Solr;
 Solr::include_client_api();
 
 use SilverStripe\Control\Director;
 use SilverStripe\FulltextSearch\Search\Indexes\SearchIndex;
+use SilverStripe\FullTextSearch\Solr\Services\SolrService;
+use SilverStripe\FulltextSearch\Search\Queries\SearchQuery;
+use SilverStripe\FullTextSearch\Search\Queries\SearchQuery_Range;
+use SilverStripe\FullTextSearch\Search\Variants\SearchVariant;
+use SilverStripe\FulltextSearch\Search\SearchIntrospection;
+use SilverStripe\ORM\ArrayList;
+use SilverStripe\ORM\DataObject;
+use SilverStripe\ORM\FieldType\DBField;
+use SilverStripe\ORM\PaginatedList;
+use SilverStripe\View\ArrayData;
 
 abstract class SolrIndex extends SearchIndex
 {
@@ -314,7 +325,7 @@ abstract class SolrIndex extends SearchIndex
     public function setFieldBoosting($field, $level)
     {
         if (!isset($this->fulltextFields[$field])) {
-            throw new InvalidArgumentException("No fulltext field $field exists on ".$this->getIndexName());
+            throw new \InvalidArgumentException("No fulltext field $field exists on ".$this->getIndexName());
         }
         if ($level === null) {
             unset($this->boostedFields[$field]);
@@ -578,7 +589,7 @@ abstract class SolrIndex extends SearchIndex
 
         foreach ($this->getClasses() as $searchclass => $options) {
             if ($searchclass == $class || ($options['include_children'] && is_subclass_of($class, $searchclass))) {
-                $base = ClassInfo::baseDataClass($searchclass);
+                $base = DataObject::getSchema()->baseDataClass($searchclass);
                 $docs[] = $this->_addAs($object, $base, $options);
             }
         }
@@ -743,7 +754,7 @@ abstract class SolrIndex extends SearchIndex
             $offset,
             $limit,
             $params,
-            Apache_Solr_Service::METHOD_POST
+            \Apache_Solr_Service::METHOD_POST
         );
 
         $results = new ArrayList();