diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 498c490beb..af36528c2d 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -639,15 +639,13 @@ function template_preprocess_datetime_wrapper(&$variables) {
  *     associative array or a string. If it's an array, it can have the
  *     following elements:
  *     - text: The heading text.
- *     - level: The heading level (e.g. 'h2', 'h3').
  *     - attributes: (optional) An array of the CSS attributes for the heading.
- *     When using a string it will be used as the text of the heading and the
- *     level will default to 'h2'. Headings should be used on navigation menus
- *     and any list of links that consistently appears on multiple pages. To
- *     make the heading invisible use the 'visually-hidden' CSS class. Do not
- *     use 'display:none', which removes it from screen readers and assistive
- *     technology. Headings allow screen reader and keyboard only users to
- *     navigate to or skip the links. See
+ *     When using a string it will be used as the text of the heading.
+ *     Headings should be used on navigation menus and any list of links that
+ *     consistently appears on multiple pages. To make the heading invisible use
+ *     the 'visually-hidden' CSS class. Do not use 'display:none', which removes
+ *     it from screen readers and assistive technology. Headings allow screen
+ *     reader and keyboard only users to navigate to or skip the links. See
  *     http://juicystudio.com/article/screen-readers-display-none.php and
  *     http://www.w3.org/TR/WCAG-TECHS/H42.html for more information.
  *
@@ -662,13 +660,12 @@ function template_preprocess_links(&$variables) {
   if (!empty($links)) {
     // Prepend the heading to the list, if any.
     if (!empty($heading)) {
-      // Convert a string heading into an array, using a <h2> tag by default.
+      // Convert a string heading into an array.
       if (is_string($heading)) {
         $heading = ['text' => $heading];
       }
       // Merge in default array properties into $heading.
       $heading += [
-        'level' => 'h2',
         'attributes' => [],
       ];
       // Convert the attributes array into an Attribute object.
diff --git a/core/modules/system/src/Tests/Theme/FunctionsTest.php b/core/modules/system/src/Tests/Theme/FunctionsTest.php
index a8fec41f21..707c540882 100644
--- a/core/modules/system/src/Tests/Theme/FunctionsTest.php
+++ b/core/modules/system/src/Tests/Theme/FunctionsTest.php
@@ -236,16 +236,15 @@ function testLinks() {
     // Verify that passing an array as heading works (core support).
     $variables['heading'] = [
       'text' => 'Links heading',
-      'level' => 'h3',
       'attributes' => ['class' => ['heading']],
     ];
-    $expected_heading = '<h3 class="heading">Links heading</h3>';
+    $expected_heading = '<h2 class="heading">Links heading</h2>';
     $expected = $expected_heading . $expected_links;
     $this->assertThemeOutput('links', $variables, $expected);
 
     // Verify that passing attributes for the heading works.
-    $variables['heading'] = ['text' => 'Links heading', 'level' => 'h3', 'attributes' => ['id' => 'heading']];
-    $expected_heading = '<h3 id="heading">Links heading</h3>';
+    $variables['heading'] = ['text' => 'Links heading', 'attributes' => ['id' => 'heading']];
+    $expected_heading = '<h2 id="heading">Links heading</h2>';
     $expected = $expected_heading . $expected_links;
     $this->assertThemeOutput('links', $variables, $expected);
 
@@ -357,16 +356,15 @@ function testIndexedKeyedLinks() {
     // Verify that passing an array as heading works (core support).
     $variables['heading'] = [
       'text' => 'Links heading',
-      'level' => 'h3',
       'attributes' => ['class' => ['heading']],
     ];
-    $expected_heading = '<h3 class="heading">Links heading</h3>';
+    $expected_heading = '<h2 class="heading">Links heading</h2>';
     $expected = $expected_heading . $expected_links;
     $this->assertThemeOutput('links', $variables, $expected);
 
     // Verify that passing attributes for the heading works.
-    $variables['heading'] = ['text' => 'Links heading', 'level' => 'h3', 'attributes' => ['id' => 'heading']];
-    $expected_heading = '<h3 id="heading">Links heading</h3>';
+    $variables['heading'] = ['text' => 'Links heading', 'attributes' => ['id' => 'heading']];
+    $expected_heading = '<h2 id="heading">Links heading</h2>';
     $expected = $expected_heading . $expected_links;
     $this->assertThemeOutput('links', $variables, $expected);
 
diff --git a/core/modules/system/templates/links.html.twig b/core/modules/system/templates/links.html.twig
index 62e9ed0b57..24912d6757 100644
--- a/core/modules/system/templates/links.html.twig
+++ b/core/modules/system/templates/links.html.twig
@@ -15,10 +15,8 @@
  *     tag if no 'url' is supplied.
  * - heading: (optional) A heading to precede the links.
  *   - text: The heading text.
- *   - level: The heading level (e.g. 'h2', 'h3').
  *   - attributes: (optional) A keyed list of attributes for the heading.
- *   If the heading is a string, it will be used as the text of the heading and
- *   the level will default to 'h2'.
+ *   If the heading is a string, it will be used as the text of the heading.
  *
  *   Headings should be used on navigation menus and any list of links that
  *   consistently appears on multiple pages. To make the heading invisible use
diff --git a/core/themes/classy/templates/content/links--node.html.twig b/core/themes/classy/templates/content/links--node.html.twig
index a7b91e7103..b2d50e751c 100644
--- a/core/themes/classy/templates/content/links--node.html.twig
+++ b/core/themes/classy/templates/content/links--node.html.twig
@@ -15,10 +15,8 @@
  *     tag if no 'href' is supplied.
  * - heading: (optional) A heading to precede the links.
  *   - text: The heading text.
- *   - level: The heading level (e.g. 'h2', 'h3').
  *   - attributes: (optional) A keyed list of attributes for the heading.
- *   If the heading is a string, it will be used as the text of the heading and
- *   the level will default to 'h2'.
+ *   If the heading is a string, it will be used as the text of the heading.
  *
  *   Headings should be used on navigation menus and any list of links that
  *   consistently appears on multiple pages. To make the heading invisible use
diff --git a/core/themes/classy/templates/navigation/links.html.twig b/core/themes/classy/templates/navigation/links.html.twig
index c1bff6bfb5..104f846196 100644
--- a/core/themes/classy/templates/navigation/links.html.twig
+++ b/core/themes/classy/templates/navigation/links.html.twig
@@ -15,10 +15,8 @@
  *     tag if no 'href' is supplied.
  * - heading: (optional) A heading to precede the links.
  *   - text: The heading text.
- *   - level: The heading level (e.g. 'h2', 'h3').
  *   - attributes: (optional) A keyed list of attributes for the heading.
- *   If the heading is a string, it will be used as the text of the heading and
- *   the level will default to 'h2'.
+ *   If the heading is a string, it will be used as the text of the heading.
  *
  *   Headings should be used on navigation menus and any list of links that
  *   consistently appears on multiple pages. To make the heading invisible use
@@ -33,11 +31,7 @@
 #}
 {% if links -%}
   {%- if heading -%}
-    {%- if heading.level -%}
-      <{{ heading.level }}{{ heading.attributes }}>{{ heading.text }}</{{ heading.level }}>
-    {%- else -%}
-      <h2{{ heading.attributes }}>{{ heading.text }}</h2>
-    {%- endif -%}
+    <h2{{ heading.attributes }}>{{ heading.text }}</h2>
   {%- endif -%}
   <ul{{ attributes }}>
     {%- for item in links -%}
diff --git a/core/themes/stable/templates/navigation/links.html.twig b/core/themes/stable/templates/navigation/links.html.twig
index c1bff6bfb5..104f846196 100644
--- a/core/themes/stable/templates/navigation/links.html.twig
+++ b/core/themes/stable/templates/navigation/links.html.twig
@@ -15,10 +15,8 @@
  *     tag if no 'href' is supplied.
  * - heading: (optional) A heading to precede the links.
  *   - text: The heading text.
- *   - level: The heading level (e.g. 'h2', 'h3').
  *   - attributes: (optional) A keyed list of attributes for the heading.
- *   If the heading is a string, it will be used as the text of the heading and
- *   the level will default to 'h2'.
+ *   If the heading is a string, it will be used as the text of the heading.
  *
  *   Headings should be used on navigation menus and any list of links that
  *   consistently appears on multiple pages. To make the heading invisible use
@@ -33,11 +31,7 @@
 #}
 {% if links -%}
   {%- if heading -%}
-    {%- if heading.level -%}
-      <{{ heading.level }}{{ heading.attributes }}>{{ heading.text }}</{{ heading.level }}>
-    {%- else -%}
-      <h2{{ heading.attributes }}>{{ heading.text }}</h2>
-    {%- endif -%}
+    <h2{{ heading.attributes }}>{{ heading.text }}</h2>
   {%- endif -%}
   <ul{{ attributes }}>
     {%- for item in links -%}