diff --git a/classes/mageekguy/atoum.php b/classes/mageekguy/atoum.php
index a4522fe..a456a9e 100644
--- a/classes/mageekguy/atoum.php
+++ b/classes/mageekguy/atoum.php
@@ -225,7 +225,7 @@ public function adapter(test\adapter $adapter) {}
      *
      * @return object
      */
-    public function newMockInstance($class, $mockNamespace = null, $mockClass = null, array $constructorArguments = null) {}
+    public function newMockInstance($class, $mockNamespace = null, $mockClass = null, ?array $constructorArguments = null) {}
 
 	/**
 	 * Allow to initialize the execution environment of the individual tests for all test method of the class.
diff --git a/classes/mageekguy/atoum/stubs/asserters/exception.php b/classes/mageekguy/atoum/stubs/asserters/exception.php
index bf70909..8adfa18 100644
--- a/classes/mageekguy/atoum/stubs/asserters/exception.php
+++ b/classes/mageekguy/atoum/stubs/asserters/exception.php
@@ -192,5 +192,5 @@ public function hasMessage($message, $failMessage = null) {}
      *
      * @return $this
      */
-    public function hasNestedException(\exception $exception = null, $failMessage = null) {}
+    public function hasNestedException(?\exception $exception = null, $failMessage = null) {}
 }