diff --git a/CHANGELOG.md b/CHANGELOG.md
index ce564a6..1e302c8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ For a full diff see [`0.6.0...master`][0.6.0...master].
 - Changed return type declaration of `NodeInterface::root()` from `self` to `static` ([#149]), by [@localheinz]
 - Added a missing return type declaration to `NodeInterface::getSize()` ([#150]), by [@localheinz]
 - Added parameter type declarations ([#151]), by [@localheinz]
+- Added property type declarations ([#152]), by [@localheinz]
 
 ## [`0.6.0`][0.6.0]
 
@@ -224,6 +225,7 @@ For a full diff see [`fcfd14e...v0.1.1`][fcfd14e...0.1.1].
 [#149]: https://github.com/nicmart/Tree/pull/149
 [#150]: https://github.com/nicmart/Tree/pull/150
 [#151]: https://github.com/nicmart/Tree/pull/151
+[#152]: https://github.com/nicmart/Tree/pull/152
 
 [@asalazar-pley]: https://github.com/asalazar-pley
 [@Djuki]: https://github.com/Djuki
diff --git a/src/Node/NodeTrait.php b/src/Node/NodeTrait.php
index e64eb56..92d76b6 100644
--- a/src/Node/NodeTrait.php
+++ b/src/Node/NodeTrait.php
@@ -15,10 +15,7 @@
 
 trait NodeTrait
 {
-    /**
-     * @var mixed
-     */
-    private $value;
+    private mixed $value = null;
     private ?NodeInterface $parent = null;
 
     /**