Service discovery protocols (SDPs) are a key component in ambient-intelligence environments: the existence of highly dynamically scenarios provokes that different devices, coming continuously in and out of them, have to discover and publish the services they either need or are able to offer. Unfortunately, the wide diversity of SDPs, associated to different platforms, makes it difficult the interoperability between services due to the impossibility of localizing and discovering to each others. This paper describes the integration of several service discovery protocols in our middleware for ambient intelligent environments. Additionally, the proposed extension for service discovery interoperability represents itself a service discovery mechanism useful to develop fully operational service discovery in our platform.