--- old/src/jdk.javadoc/share/classes/jdk/javadoc/doclet/StandardDoclet.java	2020-01-21 10:50:46.379545980 -0800
+++ new/src/jdk.javadoc/share/classes/jdk/javadoc/doclet/StandardDoclet.java	2020-01-21 10:50:46.059531839 -0800
@@ -85,7 +85,7 @@
     }
 
     @Override
-    public Set<Doclet.Option> getSupportedOptions() {
+    public Set<? extends Doclet.Option> getSupportedOptions() {
         return htmlDoclet.getSupportedOptions();
     }