diff -r b026a43e1809 -r 31ec3e55fa3d src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataRepository.java
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataRepository.java	Tue Oct 29 09:34:23 2019 +0800
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataRepository.java	Tue Oct 29 11:33:25 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, 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
@@ -255,20 +255,22 @@
         staleMetadata = true;
     }
 
-    // Lock around setOutput ensures that other threads dosn't
-    // emit event after setOutput and unregister the event class, before a call
+    // Lock around setOutput ensures that other threads don't
+    // emit events after setOutput and unregister the event class, before a call
     // to storeDescriptorInJVM
     synchronized void setOutput(String filename) {
+        if (staleMetadata) {
+            storeDescriptorInJVM();
+        }
         jvm.setOutput(filename);
 
         unregisterUnloaded();
         if (unregistered) {
-            staleMetadata = typeLibrary.clearUnregistered();
+            if (typeLibrary.clearUnregistered()) {
+                storeDescriptorInJVM();
+            }
             unregistered = false;
         }
-        if (staleMetadata) {
-            storeDescriptorInJVM();
-        }
     }
 
     private void unregisterUnloaded() {