--- old/src/java.base/share/classes/java/math/MathContext.java	2019-08-27 17:27:55.522324386 -0700
+++ new/src/java.base/share/classes/java/math/MathContext.java	2019-08-27 17:27:55.286324386 -0700
@@ -64,6 +64,7 @@
     private static final int MIN_DIGITS = 0;
 
     // Serialization version
+    @java.io.Serial
     private static final long serialVersionUID = 5579720004786848255L;
 
     /* ----- Public Properties ----- */
@@ -309,6 +310,7 @@
      *
      * @param s the stream being read.
      */
+    @java.io.Serial
     private void readObject(java.io.ObjectInputStream s)
         throws java.io.IOException, ClassNotFoundException {
         s.defaultReadObject();     // read in all fields