diff --git a/tests/commonjs_modules_caching.phpt b/tests/commonjs_caching_001.phpt
similarity index 100%
rename from tests/commonjs_modules_caching.phpt
rename to tests/commonjs_caching_001.phpt
diff --git a/tests/commonjs_caching_002.phpt b/tests/commonjs_caching_002.phpt
new file mode 100644
index 0000000..bdc34b2
--- /dev/null
+++ b/tests/commonjs_caching_002.phpt
@@ -0,0 +1,34 @@
+--TEST--
+Test V8Js::setModuleLoader : module cache seperated per isolate
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--FILE--
+<?php
+
+$JS = <<< EOT
+var foo = require("test");
+var baz = require("test");
+EOT;
+
+$v8 = new V8Js();
+$v8->setModuleLoader(function($module) {
+    print("setModuleLoader called for ".$module."\n");
+    return 'exports.bar = 23;';
+});
+
+$v8two = new V8Js();
+$v8two->setModuleLoader(function($module) {
+    print("setModuleLoader called for ".$module."\n");
+    return 'exports.bar = 23;';
+});
+
+$v8->executeString($JS, 'module.js');
+echo "--- v8two ---\n";
+$v8two->executeString($JS, 'module.js');
+?>
+===EOF===
+--EXPECT--
+setModuleLoader called for test
+--- v8two ---
+setModuleLoader called for test
+===EOF===