diff --git a/search_api_db/src/Plugin/search_api/backend/Database.php b/search_api_db/src/Plugin/search_api/backend/Database.php
index 0e761ee..cc91584 100644
--- a/search_api_db/src/Plugin/search_api/backend/Database.php
+++ b/search_api_db/src/Plugin/search_api/backend/Database.php
@@ -1813,7 +1813,7 @@ protected function createKeysQuery($keys, array $fields, array $all_fields, Inde
       // All text fields in the index share a table. Get name from the first.
       $field = reset($fields);
       $db_query = $this->database->select($field['table'], 't');
-      $mul_words = $word_count > 1;
+      $mul_words = ($word_count > 1);
       if ($neg_nested) {
         $db_query->fields('t', array('item_id', 'word'));
       }
@@ -1910,7 +1910,7 @@ protected function createKeysQuery($keys, array $fields, array $all_fields, Inde
         }
         if (!$match_parts) {
           if ($mul_words) {
-              $db_query->having('COUNT(DISTINCT t.word) >= ' . $var, array($var => $subs));
+            $db_query->having('COUNT(DISTINCT t.word) >= ' . $var, array($var => $subs));
           }
           else {
             $db_query->having('COUNT(t.word) >= ' . $var, array($var => $subs));
diff --git a/search_api_db/tests/src/Kernel/BackendTest.php b/search_api_db/tests/src/Kernel/BackendTest.php
index 4b56364..cd8c014 100644
--- a/search_api_db/tests/src/Kernel/BackendTest.php
+++ b/search_api_db/tests/src/Kernel/BackendTest.php
@@ -237,9 +237,9 @@ protected function disableHtmlFilter() {
    *
    * @param string|array|null $keys
    *   (optional) The search keys to set, if any.
-   * @param array $conditions
+   * @param string[] $conditions
    *   (optional) Conditions to set on the query, in the format "field,value".
-   * @param array|null $fields
+   * @param string[]|null $fields
    *   (optional) Fulltext fields to search for the keys.
    *
    * @return \Drupal\search_api\Query\QueryInterface