diff --git a/core/lib/Drupal/Core/Render/Element/HtmlTag.php b/core/lib/Drupal/Core/Render/Element/HtmlTag.php
index 3b9c450568c8..94a7ef18cecf 100644
--- a/core/lib/Drupal/Core/Render/Element/HtmlTag.php
+++ b/core/lib/Drupal/Core/Render/Element/HtmlTag.php
@@ -150,6 +150,8 @@ class HtmlTag extends RenderElement {
       return $element;
     }
 
+    @trigger_error('Support for IE Conditional Comments is deprecated in drupal:9.1.0 and is removed from drupal:10.0.0. See https://www.drupal.org/node/3102997', E_USER_DEPRECATED);
+
     // Determine the conditional comment expression for Internet Explorer to
     // evaluate.
     if ($browsers['IE'] === TRUE) {
diff --git a/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php b/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
index b41d7ec7a87e..0336373034dd 100644
--- a/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
@@ -251,9 +251,11 @@ class AttachedAssetsTest extends KernelTestBase {
   /**
    * Tests adding JavaScript within conditional comments.
    *
+   * @group legacy
    * @see \Drupal\Core\Render\Element\HtmlTag::preRenderConditionalComments()
    */
   public function testBrowserConditionalComments() {
+    $this->expectDeprecation('Support for IE Conditional Comments is deprecated in drupal:9.1.0 and is removed from drupal:10.0.0. See https://www.drupal.org/node/3102997');
     $default_query_string = $this->container->get('state')->get('system.css_js_query_string') ?: '0';
 
     $build['#attached']['library'][] = 'common_test/browsers';
diff --git a/core/tests/Drupal/Tests/Core/Render/Element/HtmlTagTest.php b/core/tests/Drupal/Tests/Core/Render/Element/HtmlTagTest.php
index 96777a6e70ca..67d43832f609 100644
--- a/core/tests/Drupal/Tests/Core/Render/Element/HtmlTagTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/Element/HtmlTagTest.php
@@ -206,22 +206,13 @@ class HtmlTagTest extends RendererTestBase {
     $element = [
       '#tag' => 'link',
     ];
-    $tags['link'] = [HtmlTag::preRenderConditionalComments($element), '<link />' . "\n"];
-
-    // Conditional link.
-    $element = [
-      '#tag' => 'link',
-      '#browsers' => [
-        'IE' => TRUE,
-        '!IE' => FALSE,
-      ],
-    ];
-    $tags['conditional-link'] = [HtmlTag::preRenderConditionalComments($element), "\n" . '<!--[if IE]>' . "\n" . '<link />' . "\n" . '<![endif]-->' . "\n"];
+    $tags['link'] = [$element, '<link />' . "\n"];
 
     return $tags;
   }
 
   /**
+   * @group legacy
    * @covers ::preRenderConditionalComments
    * @dataProvider providerPreRenderConditionalComments
    */