diff --git a/tests/ReCaptcha/ResponseTest.php b/tests/ReCaptcha/ResponseTest.php
index ec0a5fc..c18a8a4 100644
--- a/tests/ReCaptcha/ResponseTest.php
+++ b/tests/ReCaptcha/ResponseTest.php
@@ -112,7 +112,15 @@ public static function provideJson(): array
                 false, [ReCaptcha::E_INVALID_JSON], null, null, null, null, null,
             ],
             [
-                '{"success": false, "error-codes": "bad-request"}',
+                '{"success": false, "error-codes": "invalid-input-secret"}',
+                false, [ReCaptcha::E_UNKNOWN_ERROR], null, null, null, null, null,
+            ],
+            [
+                '{"success": false, "error-codes": null}',
+                false, [ReCaptcha::E_UNKNOWN_ERROR], null, null, null, null, null,
+            ],
+            [
+                '{"success": false, "error-codes": 123}',
                 false, [ReCaptcha::E_UNKNOWN_ERROR], null, null, null, null, null,
             ],
         ];