diff --git a/lib/nodes/ethercat.cpp b/lib/nodes/ethercat.cpp
index f56182453..c219855c4 100644
--- a/lib/nodes/ethercat.cpp
+++ b/lib/nodes/ethercat.cpp
@@ -102,6 +102,9 @@ int villas::node::ethercat_type_start(villas::node::SuperNode *sn)
 	int ret;
 	json_error_t err;
 
+	if (sn == nullptr)
+		throw RuntimeError("EtherCAT node-type requires super-node");
+
 	json_t *json = sn->getConfig();
 	if (json) {
 		ret = json_unpack_ex(json, &err, 0, "{ s?: i, s?:i, s?: { s?: { s?: i, s?: i, s?: i } } }",
diff --git a/lib/nodes/ngsi.cpp b/lib/nodes/ngsi.cpp
index 842fc062f..c40185f44 100644
--- a/lib/nodes/ngsi.cpp
+++ b/lib/nodes/ngsi.cpp
@@ -577,7 +577,8 @@ int villas::node::ngsi_type_start(villas::node::SuperNode *sn)
 	CRYPTO_set_id_callback(curl_ssl_thread_id_function);
 	CRYPTO_set_locking_callback(curl_ssl_locking_function);
 
-	sn->getLogger()->info("Setup libcurl/openssl locking primitives");
+	auto logger = logging.get("curl");
+	logger->info("Setup libcurl/openssl locking primitives");
 #endif /* CURL_SSL_REQUIRES_LOCKING */
 
 	return curl_global_init(CURL_GLOBAL_ALL);
diff --git a/lib/nodes/rtp.cpp b/lib/nodes/rtp.cpp
index daef6015f..6718c28f7 100644
--- a/lib/nodes/rtp.cpp
+++ b/lib/nodes/rtp.cpp
@@ -467,16 +467,18 @@ int villas::node::rtp_type_start(villas::node::SuperNode *sn)
 		return ret;
 
 #ifdef WITH_NETEM
-	/* Gather list of used network interfaces */
-	for (auto *n : ncp.instances) {
-		auto *nc = dynamic_cast<NodeCompat *>(n);
-		auto *r = nc->getData<struct rtp>();
-		Interface *j = Interface::getEgress(&r->out.saddr_rtp.u.sa, sn);
+	if (sn != nullptr) {
+		// Gather list of used network interfaces
+		for (auto *n : ncp.instances) {
+			auto *nc = dynamic_cast<NodeCompat *>(n);
+			auto *r = nc->getData<struct rtp>();
+			Interface *j = Interface::getEgress(&r->out.saddr_rtp.u.sa, sn);
 
-		if (!j)
-			throw RuntimeError("Failed to find egress interface");
+			if (!j)
+				throw RuntimeError("Failed to find egress interface");
 
-		j->addNode(n);
+			j->addNode(n);
+		}
 	}
 #endif /* WITH_NETEM */
 
diff --git a/lib/nodes/socket.cpp b/lib/nodes/socket.cpp
index dc3d661ee..ab09dd00f 100644
--- a/lib/nodes/socket.cpp
+++ b/lib/nodes/socket.cpp
@@ -40,18 +40,20 @@ static NodeCompatFactory ncp(&p);
 int villas::node::socket_type_start(villas::node::SuperNode *sn)
 {
 #ifdef WITH_NETEM
-	/* Gather list of used network interfaces */
-	for (auto *n : ncp.instances) {
-		auto *nc = dynamic_cast<NodeCompat *>(n);
-		auto *s = nc->getData<struct Socket>();
+	if (sn != nullptr) {
+		// Gather list of used network interfaces
+		for (auto *n : ncp.instances) {
+			auto *nc = dynamic_cast<NodeCompat *>(n);
+			auto *s = nc->getData<struct Socket>();
 
-		if (s->layer == SocketLayer::UNIX)
-			continue;
+			if (s->layer == SocketLayer::UNIX)
+				continue;
 
-		/* Determine outgoing interface */
-		Interface *j = Interface::getEgress((struct sockaddr *) &s->out.saddr, sn);
+			/* Determine outgoing interface */
+			Interface *j = Interface::getEgress((struct sockaddr *) &s->out.saddr, sn);
 
-		j->addNode(n);
+			j->addNode(n);
+		}
 	}
 #endif /* WITH_NETEM */
 
diff --git a/lib/nodes/stats.cpp b/lib/nodes/stats.cpp
index 2078639ce..c130dfdd1 100644
--- a/lib/nodes/stats.cpp
+++ b/lib/nodes/stats.cpp
@@ -9,6 +9,7 @@
 
 #include <villas/node_compat.hpp>
 #include <villas/nodes/stats.hpp>
+#include <villas/exceptions.hpp>
 #include <villas/hook.hpp>
 #include <villas/stats.hpp>
 #include <villas/super_node.hpp>
@@ -71,6 +72,9 @@ invalid_format:
 
 int villas::node::stats_node_type_start(villas::node::SuperNode *sn)
 {
+	if (sn == nullptr)
+		throw RuntimeError("Stats node-type requires super-node");
+
 	nodes = sn->getNodes();
 
 	return 0;
diff --git a/lib/nodes/websocket.cpp b/lib/nodes/websocket.cpp
index 82f858d78..c4db02617 100644
--- a/lib/nodes/websocket.cpp
+++ b/lib/nodes/websocket.cpp
@@ -14,6 +14,7 @@
 #include <libwebsockets.h>
 
 #include <villas/timing.hpp>
+#include <villas/exceptions.hpp>
 #include <villas/utils.hpp>
 #include <villas/node_compat.hpp>
 #include <villas/nodes/websocket.hpp>
@@ -333,6 +334,9 @@ int villas::node::websocket_protocol_cb(struct lws *wsi, enum lws_callback_reaso
 
 int villas::node::websocket_type_start(villas::node::SuperNode *sn)
 {
+	if (sn == nullptr)
+		throw RuntimeError("WebSocket node-type requires super-node");
+
 	web = sn->getWeb();
 	if (!web->isEnabled())
 		return -1;