diff --git a/src/vmime/net/serviceFactory.cpp b/src/vmime/net/serviceFactory.cpp
index bbc9944a..b6f90eb2 100644
--- a/src/vmime/net/serviceFactory.cpp
+++ b/src/vmime/net/serviceFactory.cpp
@@ -60,7 +60,12 @@ shared_ptr <service> serviceFactory::create
 	(shared_ptr <session> sess, const string& protocol,
 	 shared_ptr <security::authenticator> auth)
 {
-	return (getServiceByProtocol(protocol)->create(sess, auth));
+	shared_ptr <const registeredService> rserv = getServiceByProtocol(protocol);
+
+	if (!rserv)
+		throw exceptions::no_factory_available("No service is registered for protocol '" + protocol + "'.");
+
+	return rserv->create(sess, auth);
 }