diff --git a/tests/modules/upgrade_status_test_error/src/DummyTestClass.php b/tests/modules/upgrade_status_test_error/src/DummyTestClass.php
deleted file mode 100644
index fea0395..0000000
--- a/tests/modules/upgrade_status_test_error/src/DummyTestClass.php
+++ /dev/null
@@ -1,23 +0,0 @@
-<?php
-
-// @todo this is Drupal 8 to 9 specific.
-
-namespace Drupal\upgrade_status_test_error;
-
-use Drupal\simpletest\WebTestBase;
-
-/**
- * A DummyTestClass to test deprecation of WebTestBase.
- *
- * @group upgrade_status_test_error
- */
-class DummyTestClass extends WebTestBase {
-
-  /**
-   * No-op test method to make testbot happy.
-   */
-  public function testNoop() {
-
-  }
-
-}
diff --git a/tests/modules/upgrade_status_test_error/src/DeprecatedBaseClass.php b/tests/modules/upgrade_status_test_error/src/DeprecatedBaseClass.php
new file mode 100644
index 0000000..e7a995e
--- /dev/null
+++ b/tests/modules/upgrade_status_test_error/src/DeprecatedBaseClass.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Drupal\upgrade_status_test_error;
+
+/**
+ * A deprecated class to allow testing extension of deprecated classes.
+ *
+ * @group upgrade_status_test_error
+ *
+ * @deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. Instead,
+ *   use so and so. See https://www.drupal.org/project/upgrade_status.
+ */
+class DeprecatedBaseClass {
+
+}
diff --git a/tests/modules/upgrade_status_test_error/src/ExtendingClass.php b/tests/modules/upgrade_status_test_error/src/ExtendingClass.php
new file mode 100644
index 0000000..e08cd6a
--- /dev/null
+++ b/tests/modules/upgrade_status_test_error/src/ExtendingClass.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Drupal\upgrade_status_test_error;
+
+/**
+ * A dummy class to test that extension of a deprecated class is detected.
+ *
+ * @group upgrade_status_test_error
+ */
+class ExtendingClass extends DeprecatedBaseClass {
+
+}
diff --git a/tests/src/Functional/UpgradeStatusAnalyzeTest.php b/tests/src/Functional/UpgradeStatusAnalyzeTest.php
index b5a1fc3..dc0f53f 100644
--- a/tests/src/Functional/UpgradeStatusAnalyzeTest.php
+++ b/tests/src/Functional/UpgradeStatusAnalyzeTest.php
@@ -38,12 +38,24 @@ class UpgradeStatusAnalyzeTest extends UpgradeStatusTestBase {
     $this->assertCount(4, $report['data']['files']);
     $file = reset($report['data']['files']);
     $message = $file['messages'][0];
+    $this->assertEquals('fatal.php', basename(key($report['data']['files'])));
     $this->assertEquals("Syntax error, unexpected T_STRING on line 3", $message['message']);
     $this->assertEquals(3, $message['line']);
     $file = next($report['data']['files']);
+    $this->assertEquals('UpgradeStatusTestErrorController.php', basename(key($report['data']['files'])));
     $message = $file['messages'][0];
     $this->assertEquals("Call to deprecated function upgrade_status_test_no_error_deprecated_function(). Deprecated in drupal:8.6.0 and is removed from drupal:9.0.0. Use the replacement instead.", $message['message']);
     $this->assertEquals(13, $message['line']);
+    $file = next($report['data']['files']);
+    $this->assertEquals('ExtendingClass.php', basename(key($report['data']['files'])));
+    $message = $file['messages'][0];
+    $this->assertEquals("Class Drupal\upgrade_status_test_error\ExtendingClass extends deprecated class Drupal\upgrade_status_test_error\DeprecatedBaseClass. Deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. Instead, use so and so. See https://www.drupal.org/project/upgrade_status.", $message['message']);
+    $this->assertEquals(10, $message['line']);
+    $file = next($report['data']['files']);
+    $this->assertEquals('upgrade_status_test_error.info.yml', basename(key($report['data']['files'])));
+    $message = $file['messages'][0];
+    $this->assertEquals("Add core_version_requirement: ^8 || ^9 to designate that the module is compatible with Drupal 9. See https://drupal.org/node/3070687.", $message['message']);
+    $this->assertEquals(0, $message['line']);

     $report = $key_value->get('upgrade_status_test_no_error');
     $this->assertNotEmpty($report);