diff --git a/codec-http/src/main/java/io/netty/handler/codec/http/HttpClientCodec.java b/codec-http/src/main/java/io/netty/handler/codec/http/HttpClientCodec.java
index bc0680bea7..038e180259 100644
--- a/codec-http/src/main/java/io/netty/handler/codec/http/HttpClientCodec.java
+++ b/codec-http/src/main/java/io/netty/handler/codec/http/HttpClientCodec.java
@@ -21,6 +21,7 @@ import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.CombinedChannelDuplexHandler;
 import io.netty.handler.codec.PrematureChannelClosureException;
+import io.netty.util.ReferenceCountUtil;
 
 import java.util.ArrayDeque;
 import java.util.List;
@@ -87,6 +88,14 @@ public final class HttpClientCodec extends CombinedChannelDuplexHandler<HttpResp
         this.failOnMissingResponse = failOnMissingResponse;
     }
 
+    /**
+     * Prepares to upgrade to another protocol from HTTP. Disables the {@link Encoder}.
+     */
+    @Override
+    public void prepareUpgradeFrom(ChannelHandlerContext ctx) {
+        ((Encoder) outboundHandler()).upgraded = true;
+    }
+
     /**
      * Upgrades to another protocol from HTTP. Removes the {@link Decoder} and {@link Encoder} from
      * the pipeline.
@@ -107,9 +116,17 @@ public final class HttpClientCodec extends CombinedChannelDuplexHandler<HttpResp
 
     private final class Encoder extends HttpRequestEncoder {
 
+        boolean upgraded;
+
         @Override
         protected void encode(
                 ChannelHandlerContext ctx, Object msg, List<Object> out) throws Exception {
+
+            if (upgraded) {
+                out.add(ReferenceCountUtil.retain(msg));
+                return;
+            }
+
             if (msg instanceof HttpRequest && !done) {
                 queue.offer(((HttpRequest) msg).method());
             }
diff --git a/codec-http/src/main/java/io/netty/handler/codec/http/HttpClientUpgradeHandler.java b/codec-http/src/main/java/io/netty/handler/codec/http/HttpClientUpgradeHandler.java
index 1d4d74bb12..9fdf4afb85 100644
--- a/codec-http/src/main/java/io/netty/handler/codec/http/HttpClientUpgradeHandler.java
+++ b/codec-http/src/main/java/io/netty/handler/codec/http/HttpClientUpgradeHandler.java
@@ -62,6 +62,13 @@ public class HttpClientUpgradeHandler extends HttpObjectAggregator implements Ch
      * The source codec that is used in the pipeline initially.
      */
     public interface SourceCodec {
+
+        /**
+         * Removes or disables the encoder of this codec so that the {@link UpgradeCodec} can send an initial greeting
+         * (if any).
+         */
+        void prepareUpgradeFrom(ChannelHandlerContext ctx);
+
         /**
          * Removes this codec (i.e. all associated handlers) from the pipeline.
          */
@@ -222,8 +229,9 @@ public class HttpClientUpgradeHandler extends HttpObjectAggregator implements Ch
             }
 
             // Upgrade to the new protocol.
-            sourceCodec.upgradeFrom(ctx);
+            sourceCodec.prepareUpgradeFrom(ctx);
             upgradeCodec.upgradeTo(ctx, response);
+            sourceCodec.upgradeFrom(ctx);
 
             // Notify that the upgrade to the new protocol completed successfully.
             ctx.fireUserEventTriggered(UpgradeEvent.UPGRADE_SUCCESSFUL);
diff --git a/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2ConnectionHandler.java b/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2ConnectionHandler.java
index 134b1a05f9..28c1804bfd 100644
--- a/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2ConnectionHandler.java
+++ b/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2ConnectionHandler.java
@@ -47,7 +47,6 @@ import static io.netty.handler.codec.http2.Http2Stream.State.IDLE;
 import static io.netty.util.CharsetUtil.UTF_8;
 import static io.netty.util.internal.ObjectUtil.checkNotNull;
 import static java.lang.Math.min;
-import static java.lang.String.format;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 
 /**
@@ -724,20 +723,17 @@ public class Http2ConnectionHandler extends ByteToMessageDecoder implements Http
             if (future.isSuccess()) {
                 if (errorCode != NO_ERROR.code()) {
                     if (logger.isDebugEnabled()) {
-                        logger.debug(
-                                format("Sent GOAWAY: lastStreamId '%d', errorCode '%d', " +
-                                        "debugData '%s'. Forcing shutdown of the connection.",
-                                        lastStreamId, errorCode, debugData.toString(UTF_8)),
-                                        future.cause());
+                        logger.debug("{} Sent GOAWAY: lastStreamId '{}', errorCode '{}', " +
+                                     "debugData '{}'. Forcing shutdown of the connection.",
+                                     ctx.channel(), lastStreamId, errorCode, debugData.toString(UTF_8), future.cause());
                     }
                     ctx.close();
                 }
             } else {
                 if (logger.isErrorEnabled()) {
-                    logger.error(
-                            format("Sending GOAWAY failed: lastStreamId '%d', errorCode '%d', " +
-                                    "debugData '%s'. Forcing shutdown of the connection.",
-                                    lastStreamId, errorCode, debugData.toString(UTF_8)), future.cause());
+                    logger.error("{} Sending GOAWAY failed: lastStreamId '{}', errorCode '{}', " +
+                                 "debugData '{}'. Forcing shutdown of the connection.",
+                                 ctx.channel(), lastStreamId, errorCode, debugData.toString(UTF_8), future.cause());
                 }
                 ctx.close();
             }