src/java.base/share/classes/java/math/MathContext.java

@@ -62,10 +62,11 @@
     private static final RoundingMode DEFAULT_ROUNDINGMODE = RoundingMode.HALF_UP;
     // Smallest values for digits (Maximum is Integer.MAX_VALUE)
     private static final int MIN_DIGITS = 0;
 
     // Serialization version
+    @java.io.Serial
     private static final long serialVersionUID = 5579720004786848255L;
 
     /* ----- Public Properties ----- */
     /**
      *  A {@code MathContext} object whose settings have the values

@@ -307,10 +308,11 @@
      * Reconstitute the {@code MathContext} instance from a stream (that is,
      * deserialize it).
      *
      * @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
         // validate possibly bad fields
         if (precision < MIN_DIGITS) {