diff --git a/test/hotspot/jtreg/gc/g1/ihop/TestIHOPStatic.java b/test/hotspot/jtreg/gc/g1/ihop/TestIHOPStatic.java
index 6f2c7c005df..2028e8751d7 100644
--- a/test/hotspot/jtreg/gc/g1/ihop/TestIHOPStatic.java
+++ b/test/hotspot/jtreg/gc/g1/ihop/TestIHOPStatic.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 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
@@ -119,7 +119,6 @@ public class TestIHOPStatic {
         System.out.println("  MaxHeapSize : " + heapSize);
         System.out.println("  Expect for concurrent cycle initiation message : " + expectInitiationMessage);
         List<String> options = new ArrayList<>();
-        Collections.addAll(options, Utils.getTestJavaOpts());
         Collections.addAll(options,
                 "-XX:InitiatingHeapOccupancyPercent=" + ihop,
                 "-Dmemory.fill=" + (heapSize * 1024 * 1024 * pctToFill / 100),
diff --git a/test/jdk/sun/tools/jstack/DeadlockDetectionTest.java b/test/jdk/sun/tools/jstack/DeadlockDetectionTest.java
index 80eda6fc091..d743485373e 100644
--- a/test/jdk/sun/tools/jstack/DeadlockDetectionTest.java
+++ b/test/jdk/sun/tools/jstack/DeadlockDetectionTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 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
@@ -76,10 +76,8 @@ public class DeadlockDetectionTest {
         }
 
         try {
-            String[] vmArgs = Utils.appendTestJavaOpts("-XX:+UsePerfData");
-
             theApp = new LingeredAppWithDeadlock();
-            LingeredApp.startApp(theApp, vmArgs);
+            LingeredApp.startApp(theApp, "-XX:+UsePerfData");
             OutputAnalyzer output = jstack(Long.toString(theApp.getPid()));
             System.out.println(output.getOutput());
 
diff --git a/test/lib/jdk/test/lib/apps/LingeredApp.java b/test/lib/jdk/test/lib/apps/LingeredApp.java
index 38ad9ae5b0e..9a8395d7879 100644
--- a/test/lib/jdk/test/lib/apps/LingeredApp.java
+++ b/test/lib/jdk/test/lib/apps/LingeredApp.java
@@ -46,6 +46,7 @@ import java.util.UUID;
 import jdk.test.lib.JDKToolFinder;
 import jdk.test.lib.Utils;
 import jdk.test.lib.process.OutputBuffer;
+import jdk.test.lib.process.ProcessTools;
 import jdk.test.lib.process.StreamPumper;
 import jdk.test.lib.util.CoreUtils;
 
@@ -451,6 +452,7 @@ public class LingeredApp {
         long t1 = System.currentTimeMillis();
         theApp.createLock();
         try {
+            ProcessTools.checkDuplicateAgentOpts(jvmOpts);
             theApp.runAppExactJvmOpts(jvmOpts);
             theApp.waitAppReadyOrCrashed();
         } catch (Exception ex) {
diff --git a/test/lib/jdk/test/lib/cli/CommandLineOptionTest.java b/test/lib/jdk/test/lib/cli/CommandLineOptionTest.java
index 8e28ea08365..a9ae57bca71 100644
--- a/test/lib/jdk/test/lib/cli/CommandLineOptionTest.java
+++ b/test/lib/jdk/test/lib/cli/CommandLineOptionTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 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
@@ -107,7 +107,6 @@ public abstract class CommandLineOptionTest {
         List<String> finalOptions = new ArrayList<>();
         if (addTestVMOptions) {
             Collections.addAll(finalOptions, InputArguments.getVmInputArgs());
-            Collections.addAll(finalOptions, Utils.getTestJavaOpts());
         }
         Collections.addAll(finalOptions, options);
         finalOptions.add("-version");
diff --git a/test/lib/jdk/test/lib/process/ProcessTools.java b/test/lib/jdk/test/lib/process/ProcessTools.java
index 7d03268cac4..fe9c1de9f30 100644
--- a/test/lib/jdk/test/lib/process/ProcessTools.java
+++ b/test/lib/jdk/test/lib/process/ProcessTools.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 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
@@ -43,8 +43,10 @@ import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
@@ -448,7 +450,7 @@ public final class ProcessTools {
     private static ProcessBuilder createJavaProcessBuilder(String... command) {
         String javapath = JDKToolFinder.getJDKTool("java");
 
-        ArrayList<String> args = new ArrayList<>();
+        List<String> args = new ArrayList<>();
         args.add(javapath);
 
         String noCPString = System.getProperty("test.noclasspath", "false");
@@ -465,6 +467,8 @@ public final class ProcessTools {
             Collections.addAll(args, command);
         }
 
+        checkDuplicateAgentOpts(args);
+
         // Reporting
         StringBuilder cmdLine = new StringBuilder();
         for (String cmd : args)
@@ -479,6 +483,30 @@ public final class ProcessTools {
         return pb;
     }
 
+    // 8377729: Check for duplicate VM JVMTI agent options, as it may
+    // cause test to fail
+    public static void checkDuplicateAgentOpts(List<String> args) {
+        if (args == null || args.isEmpty()) {
+            return;
+        }
+
+        Set<String> seen = new HashSet<>();
+        List<String> dupArgs = args.stream()
+                .filter(arg -> (arg.startsWith("-agent")
+                                || arg.startsWith("-javaagent:"))
+                        && !seen.add(arg))
+                .collect(Collectors.toList());
+
+        if (!dupArgs.isEmpty()) {
+            System.err.println("WARNING: Duplicate JVMTI agent options may"
+                + " cause test to fail:\n" + dupArgs);
+        }
+    }
+
+    public static void checkDuplicateAgentOpts(String[] args) {
+        checkDuplicateAgentOpts(Arrays.asList(args));
+    }
+
     private static void printStack(Thread t, StackTraceElement[] stack) {
         System.out.println("\t" + t + " stack: (length = " + stack.length + ")");
         if (t != null) {