diff --git a/src/Tree.php b/src/Tree.php
index 8f36d96..25de8f0 100644
--- a/src/Tree.php
+++ b/src/Tree.php
@@ -85,8 +85,8 @@ public static function unlink(
     public static function linkChildren(
         MovableNodeContract $parent,
         iterable $children,
-        ?callable $onParentUnlinked = null,
         ?callable $key = null,
+        ?callable $onParentUnlinked = null,
     ): MovableNodeContract {
         foreach ($children as $index => $child) {
             if (!$child instanceof MovableNodeContract) {
diff --git a/tests/nodes.phpt b/tests/nodes.phpt
index 87b0acc..fa0b05c 100644
--- a/tests/nodes.phpt
+++ b/tests/nodes.phpt
@@ -173,7 +173,7 @@ require_once __DIR__ . '/setup.php';
     Assert::same($b, $e->parent());
     Assert::same([$d, $e], $b->children());
     Assert::same([], $d->children());
-    Tree::linkChildren($d, $e, function (TreeNodeContract $originalParent) use (&$hasRun, $b) {
+    Tree::linkChildren($d, $e, onParentUnlinked: function (TreeNodeContract $originalParent) use (&$hasRun, $b) {
         $hasRun = true;
         // B is the original parent of E
         Assert::same($b, $originalParent);
diff --git a/tests/tree.phpt b/tests/tree.phpt
index 4c05ea3..6d4d9b9 100644
--- a/tests/tree.phpt
+++ b/tests/tree.phpt
@@ -52,11 +52,20 @@ require_once __DIR__ . '/setup.php';
     Assert::same($one, $shouldBeOne);
 
     $counter = 0;
-    Tree::linkChildren($one, $childrenOfTwo, function ($parent) use (&$counter, $two) {
+    Tree::linkChildren($one, $childrenOfTwo, onParentUnlinked: function ($parent) use (&$counter, $two) {
         Assert::same($two, $parent);
         $counter += 1;
     });
     Assert::same(2, $counter);
+
+    // note: the parent has changed to "one"
+    Tree::linkChildren($one, $childrenOfTwo, key: fn(Node $node) => $node->data()); // key by data
+    Assert::same([
+        0 => $b,
+        1 => $c,
+        'Y' => $y,
+        'Z' => $z,
+    ], $one->children());
 })();
 
 (function () {