The current Javadocs for JDK 11 even require the module name in the URL: - eg contain `java.base`: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/time/Duration.html The current mapping issued by this plugin lacks the module name and creates https://docs.oracle.com/en/java/javase/11/docs/api/java/time/Duration.html