diff --git a/src/main/java/net/openhft/chronicle/map/TcpReplicator.java b/src/main/java/net/openhft/chronicle/map/TcpReplicator.java
index 88fcd6183..230bbce37 100644
--- a/src/main/java/net/openhft/chronicle/map/TcpReplicator.java
+++ b/src/main/java/net/openhft/chronicle/map/TcpReplicator.java
@@ -639,6 +639,12 @@ final class TcpReplicator extends AbstractChannelReplicator implements Closeable
         final SocketChannel socketChannel = (SocketChannel) key.channel();
         final Attached attached = (Attached) key.attachment();
 
+        if (attached == null) {
+            LOG.info("Closing connection " + socketChannel + ", nothing attached");
+            socketChannel.close();
+            return;
+        }
+
         try {
 
             int len = attached.entryReader.readSocketToBuffer(socketChannel);