diff --git a/Aggregation/TopHitsAggregation.php b/Aggregation/TopHitsAggregation.php
index 0dc099e8a532d97c5ee74b4ea0102a927fc50fb4..17ad36e9f17b4b2f973b6348929b0e2ab52fe859 100644
--- a/Aggregation/TopHitsAggregation.php
+++ b/Aggregation/TopHitsAggregation.php
@@ -49,7 +49,9 @@ class TopHitsAggregation extends AbstractAggregation
         parent::__construct($name);
         $this->setFrom($from);
         $this->setSize($size);
-        $this->setSort($sort);
+        if (!empty($sort)) {
+            $this->setSort($sort);
+        }
     }
 
     /**