diff --git a/modules/transport-netty4/src/test/java/org/elasticsearch/http/netty4/Netty4HttpServerPipeliningTests.java b/modules/transport-netty4/src/test/java/org/elasticsearch/http/netty4/Netty4HttpServerPipeliningTests.java
index 4f96f185a8abf..77f8ec29db514 100644
--- a/modules/transport-netty4/src/test/java/org/elasticsearch/http/netty4/Netty4HttpServerPipeliningTests.java
+++ b/modules/transport-netty4/src/test/java/org/elasticsearch/http/netty4/Netty4HttpServerPipeliningTests.java
@@ -240,37 +240,43 @@ class PossiblySlowRunnable implements Runnable {
 
         @Override
         public void run() {
-            final String uri;
-            if (pipelinedRequest != null && pipelinedRequest.last() instanceof FullHttpRequest) {
-                uri = ((FullHttpRequest) pipelinedRequest.last()).uri();
-            } else {
-                uri = fullHttpRequest.uri();
-            }
+            try {
+                final String uri;
+                if (pipelinedRequest != null && pipelinedRequest.last() instanceof FullHttpRequest) {
+                    uri = ((FullHttpRequest) pipelinedRequest.last()).uri();
+                } else {
+                    uri = fullHttpRequest.uri();
+                }
 
-            final ByteBuf buffer = Unpooled.copiedBuffer(uri, StandardCharsets.UTF_8);
+                final ByteBuf buffer = Unpooled.copiedBuffer(uri, StandardCharsets.UTF_8);
 
-            final DefaultFullHttpResponse httpResponse = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, buffer);
-            httpResponse.headers().add(HttpHeaderNames.CONTENT_LENGTH, buffer.readableBytes());
+                final FullHttpResponse httpResponse = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, buffer);
+                httpResponse.headers().add(HttpHeaderNames.CONTENT_LENGTH, buffer.readableBytes());
 
-            final boolean slow = uri.matches("/slow/\\d+");
-            if (slow) {
-                try {
-                    Thread.sleep(scaledRandomIntBetween(500, 1000));
-                } catch (InterruptedException e) {
-                    throw new RuntimeException(e);
+                final boolean slow = uri.matches("/slow/\\d+");
+                if (slow) {
+                    try {
+                        Thread.sleep(scaledRandomIntBetween(500, 1000));
+                    } catch (InterruptedException e) {
+                        throw new RuntimeException(e);
+                    }
+                } else {
+                    assert uri.matches("/\\d+");
                 }
-            } else {
-                assert uri.matches("/\\d+");
-            }
 
-            final ChannelPromise promise = ctx.newPromise();
-            final Object msg;
-            if (pipelinedRequest != null) {
-                msg = pipelinedRequest.createHttpResponse(httpResponse, promise);
-            } else {
-                msg = httpResponse;
+                final ChannelPromise promise = ctx.newPromise();
+                final Object msg;
+                if (pipelinedRequest != null) {
+                    msg = pipelinedRequest.createHttpResponse(httpResponse, promise);
+                } else {
+                    msg = httpResponse;
+                }
+                ctx.writeAndFlush(msg, promise);
+            } finally {
+                if (pipelinedRequest != null) {
+                    pipelinedRequest.release();
+                }
             }
-            ctx.writeAndFlush(msg, promise);
         }
 
     }