src/java.base/share/classes/java/util/Properties.java

@@ -140,10 +140,11 @@
 public
 class Properties extends Hashtable<Object,Object> {
     /**
      * use serialVersionUID from JDK 1.1.X for interoperability
      */
+    @java.io.Serial
     private static final long serialVersionUID = 4112578634029874840L;
 
     private static final Unsafe UNSAFE = Unsafe.getUnsafe();
 
     /**