diff --git a/netty4-client/src/main/java/redis/netty4/RedisClientBase.java b/netty4-client/src/main/java/redis/netty4/RedisClientBase.java
index a24770e..3c7f47a 100644
--- a/netty4-client/src/main/java/redis/netty4/RedisClientBase.java
+++ b/netty4-client/src/main/java/redis/netty4/RedisClientBase.java
@@ -34,12 +34,9 @@ public static Promise<RedisClientBase> connect(String host, int port) {
             new SimpleChannelInboundHandler<Reply<?>>() {
               @Override
               protected void channelRead0(ChannelHandlerContext channelHandlerContext, Reply<?> reply) throws Exception {
-                Promise<Reply> poll;
-                synchronized (client) {
-                  poll = queue.poll();
-                  if (poll == null) {
-                    throw new IllegalStateException("Promise queue is empty, received reply");
-                  }
+                Promise<Reply> poll = queue.poll();
+                if (poll == null) {
+                  throw new IllegalStateException("Promise queue is empty, received reply");
                 }
                 poll.set(reply);
               }
@@ -49,12 +46,15 @@ protected void channelRead0(ChannelHandlerContext channelHandlerContext, Reply<?
     return promise;
   }
 
-  public Promise<Reply> send(Command command) {
-    Promise<Reply> reply = new Promise<>();
-    synchronized (this) {
-      queue.add(reply);
-      socketChannel.write(command);
-    }
+  public Promise<Reply> send(final Command command) {
+    final Promise<Reply> reply = new Promise<>();
+    socketChannel.eventLoop().execute(new Runnable() {
+      @Override
+      public void run() {
+        queue.add(reply);
+        socketChannel.writeAndFlush(command);
+      }
+    });
     return reply;
   }
 }
diff --git a/netty4/pom.xml b/netty4/pom.xml
index c6e89fc..09364e5 100644
--- a/netty4/pom.xml
+++ b/netty4/pom.xml
@@ -14,12 +14,12 @@
     <dependency>
       <groupId>io.netty</groupId>
       <artifactId>netty-all</artifactId>
-      <version>4.0.10.Final</version>
+      <version>4.0.19.Final</version>
     </dependency>
     <dependency>
       <groupId>org.javassist</groupId>
       <artifactId>javassist</artifactId>
-      <version>3.18.0-GA</version>
+      <version>3.18.1-GA</version>
     </dependency>
     <dependency>
       <groupId>com.github.spullara.redis</groupId>
diff --git a/netty4/src/main/java/redis/netty4/BulkReply.java b/netty4/src/main/java/redis/netty4/BulkReply.java
index a106644..103be5b 100644
--- a/netty4/src/main/java/redis/netty4/BulkReply.java
+++ b/netty4/src/main/java/redis/netty4/BulkReply.java
@@ -28,7 +28,7 @@ public BulkReply(byte[] bytes) {
 
   public BulkReply(ByteBuf bytes) {
     this.bytes = bytes;
-    capacity = bytes.capacity();
+    capacity = bytes == null ? -1 : bytes.readableBytes();
   }
 
   @Override
diff --git a/netty4/src/main/java/redis/netty4/RedisReplyDecoder.java b/netty4/src/main/java/redis/netty4/RedisReplyDecoder.java
index f9e0ed4..dd2c78e 100644
--- a/netty4/src/main/java/redis/netty4/RedisReplyDecoder.java
+++ b/netty4/src/main/java/redis/netty4/RedisReplyDecoder.java
@@ -46,7 +46,7 @@ public ByteBuf readBytes(ByteBuf is) throws IOException {
     if (size == -1) {
       return null;
     }
-    ByteBuf buffer = is.readSlice(size);
+    ByteBuf buffer = is.readSlice(size).retain();
     int cr = is.readByte();
     int lf = is.readByte();
     if (cr != CR || lf != LF) {
@@ -128,16 +128,18 @@ public void checkpoint() {
   }
 
   public MultiBulkReply decodeMultiBulkReply(ByteBuf is) throws IOException {
-    try {
-      if (reply == null) {
-        reply = new MultiBulkReply();
+    final MultiBulkReply multiBulkReply;
+    if (reply != null) {
+      multiBulkReply = reply;
+    } else {
+      multiBulkReply = new MultiBulkReply();
+      if (checkpointEnabled) {
+        reply = multiBulkReply;
         checkpoint();
       }
-      reply.read(this, is);
-      return reply;
-    } finally {
-      reply = null;
     }
+    multiBulkReply.read(this, is);
+    reply = null;
+    return multiBulkReply;
   }
-
 }