diff --git a/transport/src/main/java/io/netty/channel/oio/AbstractOioByteChannel.java b/transport/src/main/java/io/netty/channel/oio/AbstractOioByteChannel.java
index 86f312fbb8..a64da7c631 100644
--- a/transport/src/main/java/io/netty/channel/oio/AbstractOioByteChannel.java
+++ b/transport/src/main/java/io/netty/channel/oio/AbstractOioByteChannel.java
@@ -154,7 +154,10 @@ public abstract class AbstractOioByteChannel extends AbstractOioChannel {
     protected void doWrite(ChannelOutboundBuffer in) throws Exception {
         for (;;) {
             Object msg = in.current(false);
-
+            if (msg == null) {
+                // nothing left to write
+                break;
+            }
             if (msg instanceof ByteBuf) {
                 ByteBuf buf = (ByteBuf) msg;
                 while (buf.isReadable()) {