diff --git a/core/modules/simpletest/simpletest.module b/core/modules/simpletest/simpletest.module
index d04012e..947ef26 100644
--- a/core/modules/simpletest/simpletest.module
+++ b/core/modules/simpletest/simpletest.module
@@ -244,6 +244,7 @@ function simpletest_phpunit_run_command(array $unescaped_test_classnames, $phpun
 
   $command = array(
     $phpunit_bin,
+    '--strict',
     '--filter',
     escapeshellarg($filter_string),
     '--log-junit',