diff --git a/src/NodeTrait.php b/src/NodeTrait.php
index 9d20e6b..64be271 100644
--- a/src/NodeTrait.php
+++ b/src/NodeTrait.php
@@ -671,7 +671,7 @@ public function newEloquentBuilder($query)
      *
      * @return QueryBuilder
      */
-    public function newNestedSetQuery(?string $table = null)
+    public function newNestedSetQuery($table = null)
     {
         $builder = $this->usesSoftDelete()
             ? $this->withTrashed()
@@ -681,19 +681,22 @@ public function newNestedSetQuery(?string $table = null)
     }
 
     /**
+     * @param string|null $table
+     *
      * @return QueryBuilder
      */
-    public function newScopedQuery(?string $table = null)
+    public function newScopedQuery($table = null)
     {
         return $this->applyNestedSetScope($this->newQuery(), $table);
     }
 
     /**
      * @param mixed $query
+     * @param string|null $table
      *
      * @return mixed
      */
-    public function applyNestedSetScope($query, ?string $table = null)
+    public function applyNestedSetScope($query, $table = null)
     {
         if ( ! $scoped = $this->getScopeAttributes()) {
             return $query;
@@ -745,6 +748,8 @@ public function newCollection(array $models = array())
      * {@inheritdoc}
      *
      * Use `children` key on `$attributes` to create child nodes.
+     *
+     * @param self|null $parent
      */
     public static function create(array $attributes = [], ?self $parent = null)
     {
@@ -1216,6 +1221,8 @@ protected function isSameScope(self $node): bool
     }
 
     /**
+     * @param array|null $except
+     *
      * @return \Illuminate\Database\Eloquent\Model
      */
     public function replicate(?array $except = null)
diff --git a/src/QueryBuilder.php b/src/QueryBuilder.php
index 65bf7fa..10edb27 100644
--- a/src/QueryBuilder.php
+++ b/src/QueryBuilder.php
@@ -188,7 +188,7 @@ public function ancestorsAndSelf($id, array $columns = [ '*' ])
      *
      * @return $this
      */
-    public function whereNodeBetween($values, $boolean = 'and', $not = false, ?Query $query = null)
+    public function whereNodeBetween($values, $boolean = 'and', $not = false, $query = null)
     {
         ($query ?? $this->query)->whereBetween($this->model->getTable() . '.' . $this->model->getLftName(), $values, $boolean, $not);
 
@@ -861,7 +861,7 @@ public function isBroken()
      *
      * @return int The number of changed nodes
      */
-    public function fixTree(?Model $root = null)
+    public function fixTree($root = null)
     {
         $columns = [
             $this->model->getKeyName(),
@@ -899,7 +899,7 @@ public function fixSubtree($root)
      *
      * @return int
      */
-    protected function fixNodes(array &$dictionary, ?Model $parent = null)
+    protected function fixNodes(array &$dictionary, $parent = null)
     {
         $parentId = $parent ? $parent->getKey() : null;
         $cut = $parent ? $parent->getLft() + 1 : 1;
@@ -941,7 +941,7 @@ protected function fixNodes(array &$dictionary, ?Model $parent = null)
      * @internal param int $fixed
      */
     protected static function reorderNodes(
-        array &$dictionary, array &$updated, null|int|string $parentId = null, $cut = 1
+        array &$dictionary, array &$updated, $parentId = null, $cut = 1
     ) {
         if ( ! isset($dictionary[$parentId])) {
             return $cut;
@@ -973,11 +973,11 @@ protected static function reorderNodes(
      * @param array $data
      * @param bool $delete Whether to delete nodes that exists but not in the data
      *                     array
-     * @param ?Model|NodeTrait $root
+     * @param null $root
      *
      * @return int
      */
-    public function rebuildTree(array $data, $delete = false, ?Model $root = null)
+    public function rebuildTree(array $data, $delete = false, $root = null)
     {
         if ($this->model->usesSoftDelete()) {
             $this->withTrashed();
@@ -1084,7 +1084,7 @@ protected function buildRebuildDictionary(array &$dictionary,
      *
      * @return $this
      */
-    public function applyNestedSetScope(?string $table = null)
+    public function applyNestedSetScope($table = null)
     {
         return $this->model->applyNestedSetScope($this, $table);
     }
diff --git a/tests/NodeTest.php b/tests/NodeTest.php
index c5ef004..25c6433 100644
--- a/tests/NodeTest.php
+++ b/tests/NodeTest.php
@@ -82,7 +82,7 @@ public function assertTreeNotBroken($table = 'categories')
         $this->assertEquals(array('errors' => null), $actual, "The tree structure of $table is broken!");
     }
 
-    public function dumpTree(?array $items = null)
+    public function dumpTree($items = null)
     {
         if ( ! $items) $items = Category::withTrashed()->defaultOrder()->get();