diff --git a/source/scriptinterface/ScriptInterface.cpp b/source/scriptinterface/ScriptInterface.cpp
index 2c3611ec27..e610b31aa2 100644
--- a/source/scriptinterface/ScriptInterface.cpp
+++ b/source/scriptinterface/ScriptInterface.cpp
@@ -571,7 +571,7 @@ JSObject* ScriptInterface::CreateCustomObject(const std::string& typeName) const
 		throw PSERROR_Scripting_TypeDoesNotExist();
 
 	JS::RootedObject prototype(m->m_cx, it->second.m_Prototype.get());
-	return JS_NewObject(m->m_cx, (*it).second.m_Class, prototype, JS::NullPtr());
+	return JS_NewObjectWithGivenProto(m->m_cx, it->second.m_Class, prototype);
 }
 
 bool ScriptInterface::CallFunctionVoid(JS::HandleValue val, const char* name)
diff --git a/source/simulation2/scripting/EngineScriptConversions.cpp b/source/simulation2/scripting/EngineScriptConversions.cpp
index 5389eb68b3..02661b21a6 100644
--- a/source/simulation2/scripting/EngineScriptConversions.cpp
+++ b/source/simulation2/scripting/EngineScriptConversions.cpp
@@ -182,7 +182,7 @@ template<> void ScriptInterface::ToJSVal<CFixedVector3D>(JSContext* cx, JS::Muta
 	// apply the Vector3D prototype to the return value;
  	ScriptInterface::CxPrivate* pCxPrivate = ScriptInterface::GetScriptInterfaceAndCBData(cx);
 	JS::RootedObject proto(cx, &pCxPrivate->pScriptInterface->GetCachedValue(ScriptInterface::CACHE_VECTOR3DPROTO).toObject());
-	JS::RootedObject obj(cx, JS_NewObject(cx, nullptr, proto, JS::NullPtr()));
+	JS::RootedObject obj(cx, JS_NewObjectWithGivenProto(cx, nullptr, proto));
 
 	if (!obj)
 	{
@@ -229,7 +229,7 @@ template<> void ScriptInterface::ToJSVal<CFixedVector2D>(JSContext* cx, JS::Muta
 	// apply the Vector2D prototype to the return value
  	ScriptInterface::CxPrivate* pCxPrivate = ScriptInterface::GetScriptInterfaceAndCBData(cx);
 	JS::RootedObject proto(cx, &pCxPrivate->pScriptInterface->GetCachedValue(ScriptInterface::CACHE_VECTOR2DPROTO).toObject());
-	JS::RootedObject obj(cx, JS_NewObject(cx, nullptr, proto, JS::NullPtr()));
+	JS::RootedObject obj(cx, JS_NewObjectWithGivenProto(cx, nullptr, proto));
 	if (!obj)
 	{
 		ret.setUndefined();