diff --git a/admin/picture_modify.php b/admin/picture_modify.php
index 803bc83dc..557f97dad 100644
--- a/admin/picture_modify.php
+++ b/admin/picture_modify.php
@@ -59,10 +59,11 @@ SELECT path
 if (isset($_POST['date_creation_action'])
     and 'set' == $_POST['date_creation_action'])
 {
-  if (!@checkdate(
-        $_POST['date_creation_month'],
-        $_POST['date_creation_day'],
-        $_POST['date_creation_year'])
+  if (!is_numeric($_POST['date_creation_year'])
+    or !checkdate(
+          $_POST['date_creation_month'],
+          $_POST['date_creation_day'],
+          $_POST['date_creation_year'])
     )
   {
     array_push($page['errors'], l10n('wrong date'));