diff --git a/Classes/Eel/ElasticSearchQueryBuilder.php b/Classes/Eel/ElasticSearchQueryBuilder.php
index 6c9c4917..daf1b925 100644
--- a/Classes/Eel/ElasticSearchQueryBuilder.php
+++ b/Classes/Eel/ElasticSearchQueryBuilder.php
@@ -1054,7 +1054,7 @@ protected function convertValue($value)
             return $value->getIdentifier();
         }
 
-        if ($value instanceof \DateTime) {
+        if ($value instanceof \DateTimeInterface) {
             return $value->format('Y-m-d\TH:i:sP');
         }