diff --git a/Net/include/Poco/Net/NetException.h b/Net/include/Poco/Net/NetException.h
index 770846d05..f4480e12a 100644
--- a/Net/include/Poco/Net/NetException.h
+++ b/Net/include/Poco/Net/NetException.h
@@ -71,6 +71,7 @@ POCO_DECLARE_EXCEPTION(Net_API, POP3Exception, NetException)
 POCO_DECLARE_EXCEPTION(Net_API, ICMPException, NetException)
 POCO_DECLARE_EXCEPTION(Net_API, HTMLFormException, NetException)
 POCO_DECLARE_EXCEPTION(Net_API, WebSocketException, NetException)
+POCO_DECLARE_EXCEPTION(Net_API, UnsupportedFamilyException, NetException)
 
 
 } } // namespace Poco::Net
diff --git a/Net/src/MulticastSocket.cpp b/Net/src/MulticastSocket.cpp
index e6589c677..b94d0eaaa 100644
--- a/Net/src/MulticastSocket.cpp
+++ b/Net/src/MulticastSocket.cpp
@@ -97,16 +97,18 @@ MulticastSocket& MulticastSocket::operator = (const Socket& socket)
 
 void MulticastSocket::setInterface(const NetworkInterface& interfc)
 {
-	if (!interfc.supportsIPv6())
+	if (address().family() == IPAddress::IPv4)
 	{
 		impl()->setOption(IPPROTO_IP, IP_MULTICAST_IF, interfc.firstAddress(IPAddress::IPv4));
 	}
-	else
-	{
 #if defined(POCO_HAVE_IPv6)
+	else if (address().family() == IPAddress::IPv6)
+	{
 		impl()->setOption(IPPROTO_IPV6, IPV6_MULTICAST_IF, interfc.index());
-#endif
 	}
+#endif
+	else
+		throw UnsupportedFamilyException("Unknown or unsupported socket family.");
 }
 
 	
diff --git a/Net/src/NetException.cpp b/Net/src/NetException.cpp
index b6174e964..29299870c 100644
--- a/Net/src/NetException.cpp
+++ b/Net/src/NetException.cpp
@@ -68,6 +68,7 @@ POCO_IMPLEMENT_EXCEPTION(POP3Exception, NetException, "POP3 Exception")
 POCO_IMPLEMENT_EXCEPTION(ICMPException, NetException, "ICMP Exception")
 POCO_IMPLEMENT_EXCEPTION(HTMLFormException, NetException, "HTML Form Exception")
 POCO_IMPLEMENT_EXCEPTION(WebSocketException, NetException, "WebSocket Exception")
+POCO_IMPLEMENT_EXCEPTION(UnsupportedFamilyException, NetException, "Unknown or unsupported socket family.")
 
 
 } } // namespace Poco::Net