diff --git a/src/Attributes.php b/src/Attributes.php
index ae15ef88..ffe22eea 100644
--- a/src/Attributes.php
+++ b/src/Attributes.php
@@ -365,29 +365,19 @@ public function setPrefix($prefix)
     /**
      * Register callback for an attribute
      *
-     * @param string   $name            Name of the attribute to register the callback for
-     * @param callable $callback        Callback to call when retrieving the attribute
-     * @param callable $setterCallback  Callback to call when setting the attribute
+     * @param string    $name           Name of the attribute to register the callback for
+     * @param ?callable $callback       Callback to call when retrieving the attribute
+     * @param ?callable $setterCallback Callback to call when setting the attribute
      *
      * @return $this
-     *
-     * @throws InvalidArgumentException If $callback is not callable or if $setterCallback is set and not callable
      */
-    public function registerAttributeCallback($name, $callback, $setterCallback = null)
+    public function registerAttributeCallback(string $name, ?callable $callback, ?callable $setterCallback = null): self
     {
         if ($callback !== null) {
-            if (! is_callable($callback)) {
-                throw new InvalidArgumentException(__METHOD__ . ' expects a callable callback');
-            }
-
             $this->callbacks[$name] = $callback;
         }
 
         if ($setterCallback !== null) {
-            if (! is_callable($setterCallback)) {
-                throw new InvalidArgumentException(__METHOD__ . ' expects a callable setterCallback');
-            }
-
             $this->setterCallbacks[$name] = $setterCallback;
         }
 
@@ -518,4 +508,11 @@ public function getIterator(): Traversable
     {
         return new ArrayIterator($this->attributes);
     }
+
+    public function __clone()
+    {
+        foreach ($this->attributes as &$attribute) {
+            $attribute = clone $attribute;
+        }
+    }
 }
diff --git a/src/BaseHtmlElement.php b/src/BaseHtmlElement.php
index da8348d0..41b6e4b5 100644
--- a/src/BaseHtmlElement.php
+++ b/src/BaseHtmlElement.php
@@ -352,4 +352,13 @@ public function renderUnwrapped()
             $tag
         );
     }
+
+    public function __clone()
+    {
+        parent::__clone();
+
+        if ($this->attributes !== null) {
+            $this->attributes = clone $this->attributes;
+        }
+    }
 }
diff --git a/tests/AttributesTest.php b/tests/AttributesTest.php
index 51d2c4a2..8ce23e8b 100644
--- a/tests/AttributesTest.php
+++ b/tests/AttributesTest.php
@@ -2,8 +2,11 @@
 
 namespace ipl\Tests\Html;
 
+use ipl\Html\Attribute;
 use ipl\Html\Attributes;
 use ipl\Html\BaseHtmlElement;
+use ipl\Html\HtmlString;
+use ipl\Html\ValidHtml;
 
 class AttributesTest extends TestCase
 {
@@ -113,4 +116,46 @@ function ($v) use (&$value) {
 
         $this->assertEquals(' foo="bar rab" bar="foo"', $attributes->render());
     }
+
+    public function testClone(): void
+    {
+        $original = Attributes::create([
+            'class' => 'original-class',
+            'value' => 'original-value'
+        ]);
+
+        $clone = clone $original;
+        $clone->get('class')->setValue('clone-class');
+        $clone->get('name')->setValue('clone-name');
+        $clone->remove('value');
+
+        $cloneCone = clone $clone;
+        $cloneCone->get('class')->addValue('clone-clone-class');
+        $cloneCone->get('name')->setValue('clone-clone-name');
+        $cloneCone->get('value')->setValue('clone-clone-value');
+
+        $this->assertSame('original-class', $original->get('class')->getValue());
+        $this->assertSame('original-value', $original->get('value')->getValue());
+        $this->assertNull($original->get('name')->getValue());
+        $this->assertSame(
+            ' class="original-class" value="original-value"',
+            $original->render()
+        );
+
+        $this->assertSame('clone-class', $clone->get('class')->getValue());
+        $this->assertNull($clone->get('value')->getValue());
+        $this->assertSame('clone-name', $clone->get('name')->getValue());
+        $this->assertSame(
+            ' class="clone-class" name="clone-name"',
+            $clone->render()
+        );
+
+        $this->assertSame(['clone-class', 'clone-clone-class'], $cloneCone->get('class')->getValue());
+        $this->assertSame('clone-clone-name', $cloneCone->get('name')->getValue());
+        $this->assertSame('clone-clone-value', $cloneCone->get('value')->getValue());
+        $this->assertSame(
+            ' class="clone-class clone-clone-class" name="clone-clone-name" value="clone-clone-value"',
+            $cloneCone->render()
+        );
+    }
 }