--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java	Mon Sep 09 11:43:16 2019 -0400
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java	Wed Nov 27 09:00:01 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 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
@@ -165,7 +165,9 @@
      * @return true, if given feature is a preview feature.
      */
     public boolean isPreview(Feature feature) {
-        if (feature == Feature.TEXT_BLOCKS)
+        if (feature == Feature.PATTERN_MATCHING_IN_INSTANCEOF ||
+            feature == Feature.REIFIABLE_TYPES_INSTANCEOF ||
+            feature == Feature.TEXT_BLOCKS)
             return true;
         //Note: this is a backdoor which allows to optionally treat all features as 'preview' (for testing).
         //When real preview features will be added, this method can be implemented to return 'true'