diff --git a/EthernetInterface.h b/EthernetInterface.h
index ce4a2ef..e9b6c60 100644
--- a/EthernetInterface.h
+++ b/EthernetInterface.h
@@ -65,7 +65,7 @@ class EthernetInterface {
     EthernetServer * server;
     EthernetClient clients[MAX_SOCK_NUM];                // accept up to MAX_SOCK_NUM client connections at the same time; This depends on the chipset used on the Shield
     uint8_t buffer[MAX_ETH_BUFFER+1];                    // buffer used by TCP for the recv
-    RingStream * outboundRing;
+    RingStream * outboundRing = NULL;
 };
 
 #endif