diff --git a/jetty-proxy/src/main/java/org/eclipse/jetty/proxy/AsyncMiddleManServlet.java b/jetty-proxy/src/main/java/org/eclipse/jetty/proxy/AsyncMiddleManServlet.java
index 25ec321f59f..a758275e597 100644
--- a/jetty-proxy/src/main/java/org/eclipse/jetty/proxy/AsyncMiddleManServlet.java
+++ b/jetty-proxy/src/main/java/org/eclipse/jetty/proxy/AsyncMiddleManServlet.java
@@ -53,6 +53,8 @@ import org.eclipse.jetty.util.Callback;
 import org.eclipse.jetty.util.CountingCallback;
 import org.eclipse.jetty.util.IteratingCallback;
 import org.eclipse.jetty.util.component.Destroyable;
+import org.eclipse.jetty.util.log.Log;
+import org.eclipse.jetty.util.log.Logger;
 
 /**
  * <p>Servlet 3.1 asynchronous proxy servlet with capability
@@ -757,6 +759,8 @@ public class AsyncMiddleManServlet extends AbstractProxyServlet
 
     public static class GZIPContentTransformer implements ContentTransformer
     {
+        private static final Logger logger = Log.getLogger(GZIPContentTransformer.class);
+
         private final List<ByteBuffer> buffers = new ArrayList<>(2);
         private final ContentDecoder decoder = new GZIPContentDecoder();
         private final ContentTransformer transformer;
@@ -780,6 +784,9 @@ public class AsyncMiddleManServlet extends AbstractProxyServlet
         @Override
         public void transform(ByteBuffer input, boolean finished, List<ByteBuffer> output) throws IOException
         {
+            if (logger.isDebugEnabled())
+                logger.debug("Ungzipping {} bytes, finished={}", input.remaining(), finished);
+
             if (!input.hasRemaining())
             {
                 if (finished)
@@ -790,8 +797,11 @@ public class AsyncMiddleManServlet extends AbstractProxyServlet
                 while (input.hasRemaining())
                 {
                     ByteBuffer decoded = decoder.decode(input);
-                    if (decoded.hasRemaining())
-                        transformer.transform(decoded, finished && !input.hasRemaining(), buffers);
+                    boolean complete = finished && !input.hasRemaining();
+                    if (logger.isDebugEnabled())
+                        logger.debug("Ungzipped {} bytes, complete={}", decoded.remaining(), complete);
+                    if (decoded.hasRemaining() || complete)
+                        transformer.transform(decoded, complete, buffers);
                 }
             }