diff --git a/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php b/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
index 6ca9f85..341ca06 100644
--- a/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
+++ b/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
@@ -424,4 +424,18 @@ protected function buildXPathQuery($xpath, array $args = array()) {
     return $this->assertSession()->buildXPathQuery($xpath, $args);
   }
 
+  /**
+   * Asserts whether an expected cache context was present in the last response.
+   *
+   * @param string $expected_cache_context
+   *   The expected cache context.
+   *
+   * @deprecated Scheduled for removal in Drupal 9.0.0.
+   *   Use $this->assertSession()->responseHeaderContains() instead.
+   */
+  protected function assertCacheContext($expected_cache_context) {
+    $cache_contexts = explode(' ', $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Contexts', $expected_cache_context));
+    $this->assertTrue(in_array($expected_cache_context, $cache_contexts), "'" . $expected_cache_context . "' is present in the X-Drupal-Cache-Contexts header.");
+  }
+
 }