src/java.base/share/classes/java/text/DecimalFormat.java

@@ -3868,10 +3868,11 @@
      * {@code posPrefixPattern} etc.  As a result, they will be initialized
      * to {@code null}, which means the affix strings will be taken as
      * literal values.  This is exactly what we want, since that corresponds to
      * the pre-version-2 behavior.
      */
+    @java.io.Serial
     private void readObject(ObjectInputStream stream)
          throws IOException, ClassNotFoundException
     {
         stream.defaultReadObject();
         digitList = new DigitList();

@@ -4341,7 +4342,8 @@
     // Upper limit on integer and fraction digits for BigDecimal and BigInteger
     static final int MAXIMUM_INTEGER_DIGITS  = Integer.MAX_VALUE;
     static final int MAXIMUM_FRACTION_DIGITS = Integer.MAX_VALUE;
 
     // Proclaim JDK 1.1 serial compatibility.
+    @java.io.Serial
     static final long serialVersionUID = 864413376551465018L;
 }