diff --git a/core/modules/system/tests/modules/deprecation_test/deprecation_test.info.yml b/core/modules/system/tests/modules/deprecation_test/deprecation_test.info.yml
new file mode 100644
index 0000000000..5b289513ca
--- /dev/null
+++ b/core/modules/system/tests/modules/deprecation_test/deprecation_test.info.yml
@@ -0,0 +1,6 @@
+name: 'Deprecation test'
+type: module
+description: 'Support module for testing deprecation behaviors.'
+package: Testing
+version: VERSION
+core: 8.x
diff --git a/core/modules/system/src/Deprecation/FixtureDeprecatedClass.php b/core/modules/system/tests/modules/deprecation_test/src/Deprecation/FixtureDeprecatedClass.php
similarity index 93%
rename from core/modules/system/src/Deprecation/FixtureDeprecatedClass.php
rename to core/modules/system/tests/modules/deprecation_test/src/Deprecation/FixtureDeprecatedClass.php
index c3fc24a396..65aea78250 100644
--- a/core/modules/system/src/Deprecation/FixtureDeprecatedClass.php
+++ b/core/modules/system/tests/modules/deprecation_test/src/Deprecation/FixtureDeprecatedClass.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\system\Deprecation;
+namespace Drupal\deprecation_test\Deprecation;
 
 @trigger_error(__NAMESPACE__ . '\FixtureDeprecatedClass is deprecated.', E_USER_DEPRECATED);
 
diff --git a/core/tests/Drupal/Tests/Core/Listeners/DrupalStandardsListenerDeprecationTest.php b/core/tests/Drupal/Tests/Core/Listeners/DrupalStandardsListenerDeprecationTest.php
index 744d40c7ea..622a1e0eef 100644
--- a/core/tests/Drupal/Tests/Core/Listeners/DrupalStandardsListenerDeprecationTest.php
+++ b/core/tests/Drupal/Tests/Core/Listeners/DrupalStandardsListenerDeprecationTest.php
@@ -21,7 +21,7 @@
  *
  * @group Listeners
  *
- * @coversDefaultClass \Drupal\system\Deprecation\FixtureDeprecatedClass
+ * @coversDefaultClass \Drupal\deprecation_test\Deprecation\FixtureDeprecatedClass
  */
 class DrupalStandardsListenerDeprecationTest extends UnitTestCase {