diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 6888938..ad4bd6c 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,7 +14,7 @@ jobs:
     strategy:
       max-parallel: 12
       matrix:
-        php: ['5.4', '5.5', '5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
+        php: ['5.4', '5.5', '5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2
diff --git a/lib/Peast/Selector/Matches.php b/lib/Peast/Selector/Matches.php
index b3f64df..2afa70b 100644
--- a/lib/Peast/Selector/Matches.php
+++ b/lib/Peast/Selector/Matches.php
@@ -41,7 +41,7 @@ public function __construct($matches = array())
      * @param Node $node
      * @param Node|null $parent
      */
-    public function addMatch(Node $node, Node $parent = null)
+    public function addMatch(Node $node, $parent = null)
     {
         $this->matches[] = array($node, $parent);
     }
diff --git a/lib/Peast/Selector/Node/Part/Attribute.php b/lib/Peast/Selector/Node/Part/Attribute.php
index 419d633..27a489d 100644
--- a/lib/Peast/Selector/Node/Part/Attribute.php
+++ b/lib/Peast/Selector/Node/Part/Attribute.php
@@ -135,7 +135,7 @@ public function setRegex($regex)
      *
      * @return bool
      */
-    public function check(Node $node, Node $parent = null)
+    public function check(Node $node, $parent = null)
     {
         $attr = $node;
         foreach ($this->names as $name) {
diff --git a/lib/Peast/Selector/Node/Part/Part.php b/lib/Peast/Selector/Node/Part/Part.php
index e53f083..7256d88 100644
--- a/lib/Peast/Selector/Node/Part/Part.php
+++ b/lib/Peast/Selector/Node/Part/Part.php
@@ -43,5 +43,5 @@ public function getPriority()
      *
      * @abstract
      */
-    abstract public function check(Node $node, Node $parent = null);
+    abstract public function check(Node $node, $parent = null);
 }
\ No newline at end of file
diff --git a/lib/Peast/Selector/Node/Part/PseudoIndex.php b/lib/Peast/Selector/Node/Part/PseudoIndex.php
index 952c919..6bd3e76 100644
--- a/lib/Peast/Selector/Node/Part/PseudoIndex.php
+++ b/lib/Peast/Selector/Node/Part/PseudoIndex.php
@@ -75,7 +75,7 @@ public function setOffset($offset)
      *
      * @return bool
      */
-    public function check(Node $node, Node $parent = null)
+    public function check(Node $node, $parent = null)
     {
         $props = Utils::getExpandedNodeProperties($parent);
         $count = count($props);
diff --git a/lib/Peast/Selector/Node/Part/PseudoSelector.php b/lib/Peast/Selector/Node/Part/PseudoSelector.php
index 966568e..dd9532a 100644
--- a/lib/Peast/Selector/Node/Part/PseudoSelector.php
+++ b/lib/Peast/Selector/Node/Part/PseudoSelector.php
@@ -56,7 +56,7 @@ public function setSelector(Selector $selector)
      *
      * @return bool
      */
-    public function check(Node $node, Node $parent = null)
+    public function check(Node $node, $parent = null)
     {
         $match = new Matches();
         $match->addMatch($node, $parent);
diff --git a/lib/Peast/Selector/Node/Part/PseudoSimple.php b/lib/Peast/Selector/Node/Part/PseudoSimple.php
index dcf4860..38eb3d9 100644
--- a/lib/Peast/Selector/Node/Part/PseudoSimple.php
+++ b/lib/Peast/Selector/Node/Part/PseudoSimple.php
@@ -39,7 +39,7 @@ class PseudoSimple extends Pseudo
      *
      * @return bool
      */
-    public function check(Node $node, Node $parent = null)
+    public function check(Node $node, $parent = null)
     {
         switch ($this->name) {
             case "pattern":
diff --git a/lib/Peast/Selector/Node/Part/Type.php b/lib/Peast/Selector/Node/Part/Type.php
index ffb64c4..487f634 100644
--- a/lib/Peast/Selector/Node/Part/Type.php
+++ b/lib/Peast/Selector/Node/Part/Type.php
@@ -47,7 +47,7 @@ public function setType($type)
      *
      * @return bool
      */
-    public function check(Node $node, Node $parent = null)
+    public function check(Node $node, $parent = null)
     {
         return $node->getType() === $this->type;
     }
diff --git a/lib/Peast/Syntax/CommentsRegistry.php b/lib/Peast/Syntax/CommentsRegistry.php
index 5fa46e0..f5ca0a0 100644
--- a/lib/Peast/Syntax/CommentsRegistry.php
+++ b/lib/Peast/Syntax/CommentsRegistry.php
@@ -107,7 +107,7 @@ public function onScannerResetState(&$state)
      * 
      * @return void
      */
-    public function onTokenConsumed(Token $token = null)
+    public function onTokenConsumed($token = null)
     {
         //Check if it's a comment
         if ($token && $token->type === Token::TYPE_COMMENT) {
diff --git a/lib/Peast/Syntax/Scanner.php b/lib/Peast/Syntax/Scanner.php
index 890753c..86678b3 100644
--- a/lib/Peast/Syntax/Scanner.php
+++ b/lib/Peast/Syntax/Scanner.php
@@ -614,7 +614,7 @@ public function getPosition($scanPosition = false)
      * 
      * @return $this
      */
-    public function setScanPosition(Position $position = null)
+    public function setScanPosition(Position $position)
     {
         $this->line = $position->getLine();
         $this->column = $position->getColumn();