diff --git a/core/includes/form.inc b/core/includes/form.inc
index efbac99..aaaeb17 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -257,6 +257,12 @@ function template_preprocess_details(&$variables) {
   $variables['description'] = (!empty($element['#description'])) ? $element['#description'] : '';
   $variables['children'] = (isset($element['#children'])) ? $element['#children'] : '';
   $variables['value'] = (isset($element['#value'])) ? $element['#value'] : '';
+
+  // Display any error messages.
+  $variables['errors'] = NULL;
+  if (!empty($element['#errors']) && empty($element['#error_no_message'])) {
+    $variables['errors'] = $element['#errors'];
+  }
 }
 
 /**
diff --git a/core/modules/system/src/Tests/Form/ElementTest.php b/core/modules/system/src/Tests/Form/ElementTest.php
index 6555a4f..07cf1e9 100644
--- a/core/modules/system/src/Tests/Form/ElementTest.php
+++ b/core/modules/system/src/Tests/Form/ElementTest.php
@@ -160,4 +160,13 @@ public function testFormAutocomplete() {
     $this->assertEqual(count($result), 1, 'Ensure that the user does have access to the autocompletion');
   }
 
+  /**
+   * Tests form element error messages.
+   */
+  public function testFormElementErrors() {
+    $edit = ['error_on_details' => '1'];
+    $this->drupalPostForm('form-test/group-container', $edit, 'Submit');
+    $this->assertText('I am an error on the details element.');
+  }
+
 }
diff --git a/core/modules/system/templates/details.html.twig b/core/modules/system/templates/details.html.twig
index 1c0fd79..cf50eb0 100644
--- a/core/modules/system/templates/details.html.twig
+++ b/core/modules/system/templates/details.html.twig
@@ -5,6 +5,7 @@
  *
  * Available variables
  * - attributes: A list of HTML attributes for the details element.
+ * - errors: (optional) Any errors for this details element, may not be set.
  * - title: (optional) The title of the element, may not be set.
  * - description: (optional) The description of the element, may not be set.
  * - children: (optional) The children of the element, may not be set.
@@ -20,6 +21,12 @@
     <summary{{ summary_attributes }}>{{ title }}</summary>
   {%- endif -%}
 
+  {% if errors %}
+    <div>
+      {{ errors }}
+    </div>
+  {% endif %}
+
   {{ description }}
   {{ children }}
   {{ value }}
diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestGroupContainerForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestGroupContainerForm.php
index 26a04c4..5ffd00c 100644
--- a/core/modules/system/tests/modules/form_test/src/Form/FormTestGroupContainerForm.php
+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestGroupContainerForm.php
@@ -39,12 +39,26 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#type' => 'textfield',
       '#title' => 'Nest in details element',
     );
+    $form['error_on_details'] = array(
+      '#type' => 'checkbox',
+      '#title' => 'Show error on details',
+    );
+    $form['submit'] = array('#type' => 'submit', '#value' => 'Submit');
     return $form;
   }
 
   /**
    * {@inheritdoc}
    */
+  public function validateForm(array &$form, FormStateInterface $form_state) {
+    if ($form_state->getValue('error_on_details') == True) {
+      $form_state->setErrorByName('meta', 'I am an error on the details element.');
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function submitForm(array &$form, FormStateInterface $form_state) {
   }
 
diff --git a/core/themes/classy/templates/form/details.html.twig b/core/themes/classy/templates/form/details.html.twig
index 9b149d7..a4ce6f6 100644
--- a/core/themes/classy/templates/form/details.html.twig
+++ b/core/themes/classy/templates/form/details.html.twig
@@ -5,6 +5,7 @@
  *
  * Available variables
  * - attributes: A list of HTML attributes for the details element.
+ * - errors: (optional) Any errors for this details element, may not be set.
  * - title: (optional) The title of the element, may not be set.
  * - description: (optional) The description of the element, may not be set.
  * - children: (optional) The children of the element, may not be set.
@@ -18,6 +19,11 @@
     <summary{{ summary_attributes }}>{{ title }}</summary>
   {%- endif -%}
   <div class="details-wrapper">
+    {% if errors %}
+      <div class="form-item--error-message">
+        <strong>{{ errors }}</strong>
+      </div>
+    {% endif %}
     {%- if description -%}
       <div class="details-description">{{ description }}</div>
     {%- endif -%}