diff --git a/src/Tests/EncryptTestBase.php b/src/Tests/EncryptTestBase.php
index 6d383c8..6f6006f 100644
--- a/src/Tests/EncryptTestBase.php
+++ b/src/Tests/EncryptTestBase.php
@@ -81,7 +81,7 @@ abstract class EncryptTestBase extends WebTestBase {
       'id' => 'testing_key_256',
       'label' => 'Testing Key 256 bit',
       'key_type' => "encryption",
-      'key_type_settings[key_size]' => ['key_size' => '256'],
+      'key_type_settings' => ['key_size' => '256'],
       'key_provider' => 'config',
       'key_provider_settings' => ['key_value' => 'mustbesixteenbitmustbesixteenbit'],
     ]);