diff --git a/Models/IncomeStatement.php b/Models/IncomeStatement.php
index a65cba9..6f34567 100644
--- a/Models/IncomeStatement.php
+++ b/Models/IncomeStatement.php
@@ -32,7 +32,7 @@ class IncomeStatement
      */
     protected int $id = 0;
 
-    private $date = null;
+    private ?\DateTime $date = null;
 
-    private $incomeStatement = [];
+    private array $incomeStatement = [];
 }