diff --git a/core/modules/system/tests/src/Functional/Form/ElementsContainerTest.php b/core/modules/system/tests/src/Functional/Form/ElementsContainerTest.php
index 64deb40..cb87569 100644
--- a/core/modules/system/tests/src/Functional/Form/ElementsContainerTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ElementsContainerTest.php
@@ -23,23 +23,10 @@ class ElementsContainerTest extends BrowserTestBase {
    */
   public function testOptionalContainerElements() {
     $this->drupalGet('form-test/optional-container');
-
-    // Assert that an empty optional container is not shown.
-    $elements =$this->assertSession()->elementExists('css', 'div.empty_optional');
-    $this->assertTrue(count($elements) == 0);
-
-    // empty_nonoptional
-    $elements = $this->assertSession()->elementExists('css', 'div.empty_nonoptional');
-    $this->assertTrue(count($elements) == 1);
-
-    // nonempty_optional
-    $elements = $this->assertSession()->elementExists('css', 'div.nonempty_optional');
-    $this->assertTrue(count($elements) == 1);
-
-    // nonempty_nonoptional
-    $elements = $this->assertSession()->elementExists('css', 'div.nonempty_nonoptional');
-    $this->assertTrue(count($elements) == 1);
-
+    $this->assertSession()->elementNotExists('css', 'div.empty_optional');
+    $this->assertSession()->elementExists('css', 'div.empty_nonoptional');
+    $this->assertSession()->elementExists('css', 'div.nonempty_optional');
+    $this->assertSession()->elementExists('css', 'div.nonempty_nonoptional');
   }
 
 }