diff --git a/test/jdk/java/net/httpclient/HeadTest.java b/test/jdk/java/net/httpclient/HeadTest.java
index 3e05442faf5..c8ab0da27f0 100644
--- a/test/jdk/java/net/httpclient/HeadTest.java
+++ b/test/jdk/java/net/httpclient/HeadTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -22,14 +22,26 @@
  */
 
 /*
- * @test
+ * @test id=withCertificateCompression
  * @bug 8203433 8276559
  * @summary Tests Client handles HEAD and 304 responses correctly.
  * @library /test/lib /test/jdk/java/net/httpclient/lib
  * @build jdk.test.lib.net.SimpleSSLContext
- * @run testng/othervm -Djdk.httpclient.HttpClient.log=trace,headers,requests HeadTest
+ * @run testng/othervm -Djdk.tls.enableCertificateCompression=true
+ *                     -Djdk.httpclient.HttpClient.log=trace,headers,requests HeadTest
  */
 
+/*
+ * @test id=withoutCertificateCompression
+ * @bug 8203433 8276559
+ * @summary Tests Client handles HEAD and 304 responses correctly.
+ * @library /test/lib /test/jdk/java/net/httpclient/lib
+ * @build jdk.test.lib.net.SimpleSSLContext
+ * @run testng/othervm -Djdk.tls.enableCertificateCompression=false
+ *                     -Djdk.httpclient.HttpClient.log=trace,headers,requests HeadTest
+ */
+
+
 import jdk.test.lib.net.SimpleSSLContext;
 import org.testng.annotations.AfterTest;
 import org.testng.annotations.BeforeTest;
diff --git a/test/jdk/java/net/httpclient/LargeHandshakeTest.java b/test/jdk/java/net/httpclient/LargeHandshakeTest.java
index ff3981e8b3d..5d305aeb1e1 100644
--- a/test/jdk/java/net/httpclient/LargeHandshakeTest.java
+++ b/test/jdk/java/net/httpclient/LargeHandshakeTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -66,8 +66,8 @@ import static java.net.http.HttpClient.Version.HTTP_3;
 import static java.net.http.HttpOption.Http3DiscoveryMode.HTTP_3_URI_ONLY;
 import static java.net.http.HttpOption.H3_DISCOVERY;
 
-/**
- * @test
+/*
+ * @test id=withCertificateCompression
  * @bug 8231449
  * @summary This test verifies that the HttpClient works correctly when the server
  *          sends a large certificate. This test will not pass without
@@ -84,13 +84,42 @@ import static java.net.http.HttpOption.H3_DISCOVERY;
  * @build jdk.httpclient.test.lib.common.HttpServerAdapters jdk.test.lib.net.SimpleSSLContext
  *        DigestEchoServer
  *        jdk.httpclient.test.lib.common.TestServerConfigurator
- * @run main/othervm -Dtest.requiresHost=true
+ * @run main/othervm -Djdk.tls.enableCertificateCompression=true
+ *                   -Dtest.requiresHost=true
  *                   -Djdk.httpclient.HttpClient.log=headers
  *                   -Djdk.internal.httpclient.debug=true
  *                   -Djdk.tls.maxHandshakeMessageSize=131072
  *                   LargeHandshakeTest
  *
  */
+
+/*
+ * @test id=withoutCertificateCompression
+ * @bug 8231449
+ * @summary This test verifies that the HttpClient works correctly when the server
+ *          sends a large certificate. This test will not pass without
+ *          the fix for JDK-8231449. To regenerate the certificate, modify the
+ *          COMMAND constant as you need, possibly changing the start date
+ *          and validity of the certificate in the command, then run the test.
+ *          The test will run with the old certificate, but will print the new command.
+ *          Copy paste the new command printed by this test into a terminal.
+ *          Then modify the at run line to pass the file generated by that command
+ *          as first argument, and copy paste the new values of the COMMAND and
+ *          BASE64_CERT constant printed by the test into the test.
+ *          Then restore the original at run line and test again.
+ * @library /test/lib /test/jdk/java/net/httpclient/lib
+ * @build jdk.httpclient.test.lib.common.HttpServerAdapters jdk.test.lib.net.SimpleSSLContext
+ *        DigestEchoServer
+ *        jdk.httpclient.test.lib.common.TestServerConfigurator
+ * @run main/othervm -Djdk.tls.enableCertificateCompression=false
+ *                   -Dtest.requiresHost=true
+ *                   -Djdk.httpclient.HttpClient.log=headers
+ *                   -Djdk.internal.httpclient.debug=true
+ *                   -Djdk.tls.maxHandshakeMessageSize=131072
+ *                   LargeHandshakeTest
+ *
+ */
+
 public class LargeHandshakeTest implements HttpServerAdapters {
 
     // Use this command to regenerate the keystore file whose content is