diff --git a/Transformer/DateFormatTransformer.php b/Transformer/DateFormatTransformer.php
index 5b0739b2..7f6a097a 100644
--- a/Transformer/DateFormatTransformer.php
+++ b/Transformer/DateFormatTransformer.php
@@ -41,7 +41,7 @@ public function transform($value, array $options = [])
             return $value;
         }
 
-        if ($value instanceof \DateTime) {
+        if ($value instanceof \DateTimeInterface) {
             $date = $value;
         } elseif (is_string($value)) {
             @trigger_error('String input will be deprecated in v4.0', E_USER_DEPRECATED);