diff --git a/tests/lib/SimpleSAML/Utils/SystemTest.php b/tests/lib/SimpleSAML/Utils/SystemTest.php
index 8b98c63008a58a6c26a4b9bbbe37379baf6e4122..9f73b88fd45a2804a87902c4abca85d587b3c817 100644
--- a/tests/lib/SimpleSAML/Utils/SystemTest.php
+++ b/tests/lib/SimpleSAML/Utils/SystemTest.php
@@ -152,11 +152,13 @@ class SystemTest extends TestCase
     /**
      * @covers \SimpleSAML\Utils\System::writeFile
      * @test
+     * @deprecated Test becomes obsolete as soon as the codebase is fully type hinted
      * @return void
      */
     public function testWriteFileInvalidArguments()
     {
         $this->expectException(\InvalidArgumentException::class);
+        /** @psalm-suppress NullArgument */
         System::writeFile(null, null, null);
     }