src/java.base/share/classes/java/io/IOException.java

*** 35,44 ****
--- 35,45 ----
   * @see     java.io.OutputStream
   * @since   1.0
   */
  public
  class IOException extends Exception {
+     @java.io.Serial
      static final long serialVersionUID = 7818375828146090155L;
  
      /**
       * Constructs an {@code IOException} with {@code null}
       * as its error detail message.