diff --git a/src/Parser.php b/src/Parser.php
index f3d6e50..c32395f 100644
--- a/src/Parser.php
+++ b/src/Parser.php
@@ -25,7 +25,7 @@ class Parser
     private array $macro     = [];
     private array $variables = [];
 
-    public function __construct(Lexer $lexer = null)
+    public function __construct(?Lexer $lexer = null)
     {
         $this->lexer = $lexer ?: new Lexer();
     }
@@ -153,7 +153,7 @@ private function parseObject(): ObjectNode
      * KeyValueList ::= VariableAssignation|KeyValue [ Separator [ KeyValueList ] ]
      * KeyValue     ::= ( ( T_END_STR | T_NAME ) OptionalAssignementOperator Value ) | MacroCall
      */
-    private function parseInnerObject(ObjectNode $object = null): ObjectNode
+    private function parseInnerObject(?ObjectNode $object = null): ObjectNode
     {
         $object = $object ?: new ObjectNode();
         do {
diff --git a/tests/NaclTest.php b/tests/NaclTest.php
index d32710a..127ef37 100644
--- a/tests/NaclTest.php
+++ b/tests/NaclTest.php
@@ -54,7 +54,7 @@ public function testNacl(string $naclFile, string $jsonFile): void
 
         $this->parser->registerMacro(new Macros\Callback('testMacroWithOptions', fn($p, $a = []) => [
             'param'   => $p,
-            'options' => $a
+            'options' => $a,
         ]));
 
         $this->parser->registerMacro(new Macros\Callback('testMacro', fn($p, $a = []) => $p));