--- old/test/hotspot/jtreg/gc/logging/TestGCId.java	2018-11-26 21:30:28.737882015 +0100
+++ new/test/hotspot/jtreg/gc/logging/TestGCId.java	2018-11-26 21:30:28.587883338 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2018, 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
@@ -41,6 +41,7 @@
     testGCId("UseG1GC");
     testGCId("UseConcMarkSweepGC");
     testGCId("UseSerialGC");
+    testGCId("UseShenandoahGC");
   }
 
   private static void verifyContainsGCIDs(OutputAnalyzer output) {
@@ -51,7 +52,7 @@
 
   private static void testGCId(String gcFlag) throws Exception {
     ProcessBuilder pb_default =
-      ProcessTools.createJavaProcessBuilder("-XX:+" + gcFlag, "-Xlog:gc", "-Xmx10M", GCTest.class.getName());
+      ProcessTools.createJavaProcessBuilder("-XX:+UnlockExperimentalVMOptions", "-XX:+" + gcFlag, "-Xlog:gc", "-Xmx10M", GCTest.class.getName());
     verifyContainsGCIDs(new OutputAnalyzer(pb_default.start()));
   }