diff --git a/src/Form.php b/src/Form.php
index 6909286..58124ff 100644
--- a/src/Form.php
+++ b/src/Form.php
@@ -613,7 +613,7 @@ class Form
             return $inputDate;
         }
         $errors = $date->getLastErrors();
-        if ($errors["warning_count"] > 0 || $errors["error_count"] > 0) {
+        if (is_array($errors) && ($errors["warning_count"] > 0 || $errors["error_count"] > 0)) {
             return $inputDate;
         }
         return $date->format($outputFormat);