--- old/src/java.base/share/classes/java/nio/file/FileSystemAlreadyExistsException.java	2019-08-27 17:28:13.426324386 -0700
+++ new/src/java.base/share/classes/java/nio/file/FileSystemAlreadyExistsException.java	2019-08-27 17:28:13.254324386 -0700
@@ -35,6 +35,7 @@
 public class FileSystemAlreadyExistsException
     extends RuntimeException
 {
+    @java.io.Serial
     static final long serialVersionUID = -5438419127181131148L;
 
     /**