--- a/test/hotspot/jtreg/serviceability/sa/ClhsdbLauncher.java	Thu Oct 03 18:59:56 2019 +0100
+++ b/test/hotspot/jtreg/serviceability/sa/ClhsdbLauncher.java	Fri Oct 04 07:54:57 2019 +0100
@@ -140,6 +140,7 @@
         for (String cmd : commands) {
             int index = commands.indexOf(cmd) + 1;
             OutputAnalyzer out = new OutputAnalyzer(parts[index]);
+            out.shouldNotMatch("Unrecognized command.");
 
             if (expectedStrMap != null) {
                 List<String> expectedStr = expectedStrMap.get(cmd);