diff --git a/core/lib/Drupal/Core/Template/AttributeBoolean.php b/core/lib/Drupal/Core/Template/AttributeBoolean.php
index 4e9ea67..d3d4a45 100644
--- a/core/lib/Drupal/Core/Template/AttributeBoolean.php
+++ b/core/lib/Drupal/Core/Template/AttributeBoolean.php
@@ -39,6 +39,13 @@ public function render() {
   }
 
   /**
+   * Returns the boolean value.
+   */
+  public function value() {
+    return $this->value;
+  }
+
+  /**
    * Implements the magic __toString() method.
    */
   public function __toString() {
diff --git a/core/tests/Drupal/Tests/Core/Template/AttributeTest.php b/core/tests/Drupal/Tests/Core/Template/AttributeTest.php
index a8a64ab..249b79f 100644
--- a/core/tests/Drupal/Tests/Core/Template/AttributeTest.php
+++ b/core/tests/Drupal/Tests/Core/Template/AttributeTest.php
@@ -78,6 +78,11 @@ public function testSetAttribute() {
     $attribute = new Attribute();
     $attribute->setAttribute('class', array('kitten', 'cat'));
     $this->assertArrayEquals(array('kitten', 'cat'), $attribute['class']->value());
+
+    // Test adding boolean attributes.
+    $attribute = new Attribute();
+    $attribute['checked'] = TRUE;
+    $this->assertTrue($attribute['checked']->value());
   }
 
   /**
@@ -92,6 +97,7 @@ public function testRemoveAttribute() {
       'style' => 'color: pink;',
       'title' => 'kitten',
       'value' => 'ostrich',
+      'checked' => TRUE,
     );
     $attribute = new Attribute($attributes);
 
@@ -111,6 +117,10 @@ public function testRemoveAttribute() {
     // Multiple values in array.
     $attribute->removeAttribute(['title', 'value']);
     $this->assertEmpty((string) $attribute);
+
+    // Boolean value.
+    $attribute->removeAttribute('checked');
+    $this->assertEmpty($attribute['checked']);
   }
 
   /**