diff --git a/libp2p/NodeTable.h b/libp2p/NodeTable.h
index 5a5690ddb..c35c9cc36 100644
--- a/libp2p/NodeTable.h
+++ b/libp2p/NodeTable.h
@@ -276,10 +276,11 @@ inline std::ostream& operator<<(std::ostream& _out, NodeTable const& _nodeTable)
 	return _out;
 }
 
-struct InvalidDiscoveryPacket: Exception { using Exception::Exception; };
+struct InvalidDiscoveryPacket: Exception { public: using Exception::Exception; };
 
 struct DiscoveryDatagram: public RLPXDatagramFace
 {
+public:
 	/// Constructor used for sending.
 	DiscoveryDatagram(bi::udp::endpoint const& _ep): RLPXDatagramFace(_ep), ts(futureFromEpoch(std::chrono::seconds(60))) {}
 
@@ -308,7 +309,7 @@ struct DiscoveryDatagram: public RLPXDatagramFace
  * If the pinged node doesn't respond, then it is removed and the new
  * node is inserted.
  */
-struct PingNode: DiscoveryDatagram
+struct PingNode: public DiscoveryDatagram
 {
 	using DiscoveryDatagram::DiscoveryDatagram;
 	PingNode(NodeIPEndpoint _src, NodeIPEndpoint _dest): DiscoveryDatagram(_dest), source(_src), destination(_dest) {}
@@ -341,7 +342,7 @@ struct PingNode: DiscoveryDatagram
 /**
  * Pong packet: Sent in response to ping
  */
-struct Pong: DiscoveryDatagram
+struct Pong: public DiscoveryDatagram
 {
 	using DiscoveryDatagram::DiscoveryDatagram;
 	Pong(NodeIPEndpoint const& _dest): DiscoveryDatagram((bi::udp::endpoint)_dest), destination(_dest) {}
@@ -379,7 +380,7 @@ struct Pong: DiscoveryDatagram
  * target: NodeID of node. The responding node will send back nodes closest to the target.
  *
  */
-struct FindNode: DiscoveryDatagram
+struct FindNode: public DiscoveryDatagram
 {
 	using DiscoveryDatagram::DiscoveryDatagram;
 	FindNode(bi::udp::endpoint _ep, h512 _target): DiscoveryDatagram(_ep), target(_target) {}