diff -u b/core/tests/Drupal/KernelTests/KernelTestBase.php b/core/tests/Drupal/KernelTests/KernelTestBase.php
--- b/core/tests/Drupal/KernelTests/KernelTestBase.php
+++ b/core/tests/Drupal/KernelTests/KernelTestBase.php
@@ -739,7 +739,7 @@
   protected function enableModules(array $modules) {
     $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
     if ($trace[1]['function'] === 'setUp') {
-      trigger_error('KernelTestBase::enableModules() should not be called from setUp(). Use the $modules property instead.', E_DEPRECATED);
+      trigger_error('KernelTestBase::enableModules() should not be called from setUp(). Use the $modules property instead.', E_USER_DEPRECATED);
     }
     unset($trace);