diff --git a/.fernignore b/.fernignore
index 33bb080..57a0d2f 100644
--- a/.fernignore
+++ b/.fernignore
@@ -1,3 +1,6 @@
 # Specify files that shouldn't be modified by Fern
 LICENSE.md
 CONTRIBUTING.md
+
+# nullable DateTime fix
+src/Core/Json/JsonSerializableType.php
diff --git a/src/Core/Json/JsonSerializableType.php b/src/Core/Json/JsonSerializableType.php
index a555b67..445d0bb 100644
--- a/src/Core/Json/JsonSerializableType.php
+++ b/src/Core/Json/JsonSerializableType.php
@@ -145,6 +145,10 @@ public static function jsonDeserialize(array $data): static
             $dateTypeAttr = $property->getAttributes(Date::class)[0] ?? null;
             if ($dateTypeAttr) {
                 $dateType = $dateTypeAttr->newInstance()->type;
+                if ($value === null) {
+                    $args[$property->getName()] = null;
+                    continue;
+                }
                 if (!is_string($value)) {
                     throw new JsonException("Unexpected non-string type for date.");
                 }