--- old/src/java.base/share/classes/java/util/FormatFlagsConversionMismatchException.java	2019-08-27 17:28:55.946324386 -0700
+++ new/src/java.base/share/classes/java/util/FormatFlagsConversionMismatchException.java	2019-08-27 17:28:55.742324386 -0700
@@ -37,6 +37,7 @@
 public class FormatFlagsConversionMismatchException
     extends IllegalFormatException
 {
+    @java.io.Serial
     private static final long serialVersionUID = 19120414L;
 
     private String f;