diff --git a/libp2p/Session.cpp b/libp2p/Session.cpp
index 12f48f3c9..d6a45bfc7 100644
--- a/libp2p/Session.cpp
+++ b/libp2p/Session.cpp
@@ -86,7 +86,13 @@ bool Session::interpret(RLP const& _r)
 		m_listenPort = _r[4].toInt<unsigned short>();
 		m_id = _r[5].toHash<h512>();
 
-		clogS(NetMessageSummary) << "Hello: " << clientVersion << "V[" << m_protocolVersion << "]" << m_id.abridged() << showbase << hex << caps << dec << m_listenPort;
+		// clang error (previously: ... << hex << caps ...)
+		// "'operator<<' should be declared prior to the call site or in an associated namespace of one of its arguments"
+		stringstream capslog;
+		for (auto cap: caps)
+			capslog << "(" << hex << cap.first << "," << hex << cap.second << ")";
+
+		clogS(NetMessageSummary) << "Hello: " << clientVersion << "V[" << m_protocolVersion << "]" << m_id.abridged() << showbase << capslog.str() << dec << m_listenPort;
 
 		if (m_server->havePeer(m_id))
 		{