diff --git a/test/hotspot/jtreg/serviceability/jvmti/valhalla/HeapDump/HeapDump.java b/test/hotspot/jtreg/serviceability/jvmti/valhalla/HeapDump/HeapDump.java
index 28bf9c82165..0b2ec0ad503 100644
--- a/test/hotspot/jtreg/serviceability/jvmti/valhalla/HeapDump/HeapDump.java
+++ b/test/hotspot/jtreg/serviceability/jvmti/valhalla/HeapDump/HeapDump.java
@@ -149,8 +149,9 @@ public static void main(String[] args) throws Throwable {
         try {
             theApp = new HeapDumpTarg();
 
-            // -XX:+PrintInlineLayout is debug-only arg
-            LingeredApp.startApp(theApp, "--enable-preview", "-XX:+PrintInlineLayout", "-XX:+PrintFlatArrayLayout",
+            LingeredApp.startApp(theApp, "--enable-preview",
+                                 "-XX:+UnlockDiagnosticVMOptions",
+                                 "-XX:+PrintInlineLayout", "-XX:+PrintFlatArrayLayout",
                                  "--add-modules=java.base",
                                  "--add-exports=java.base/jdk.internal.value=ALL-UNNAMED");