diff --git a/tests/issue_183_005.phpt b/tests/issue_183_005.phpt
new file mode 100644
index 0000000..2cff423
--- /dev/null
+++ b/tests/issue_183_005.phpt
@@ -0,0 +1,19 @@
+--TEST--
+Test V8::executeString() : Method access on derived classes (__sleep)
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--FILE--
+<?php
+
+class Foo extends \V8Js
+{
+    public function __sleep()
+    {
+	var_dump("foo");
+    }
+}
+
+?>
+===EOF===
+--EXPECTF--
+Fatal error: Cannot override final method V8Js::__sleep() in %s
diff --git a/tests/issue_183_006.phpt b/tests/issue_183_006.phpt
new file mode 100644
index 0000000..395e905
--- /dev/null
+++ b/tests/issue_183_006.phpt
@@ -0,0 +1,19 @@
+--TEST--
+Test V8::executeString() : Method access on derived classes (__wakeup)
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--FILE--
+<?php
+
+class Foo extends \V8Js
+{
+    public function __wakeup()
+    {
+	var_dump("foo");
+    }
+}
+
+?>
+===EOF===
+--EXPECTF--
+Fatal error: Cannot override final method V8Js::__wakeup() in %s