src/java.base/share/classes/java/time/Clock.java

@@ -639,10 +639,11 @@
      * Implementation of a clock that adds an offset to an underlying clock.
      */
     static final class OffsetClock extends Clock implements Serializable {
         @java.io.Serial
         private static final long serialVersionUID = 2007484719125426256L;
+        @SuppressWarnings("serial") // Not statically typed as Serializable
         private final Clock baseClock;
         private final Duration offset;
 
         OffsetClock(Clock baseClock, Duration offset) {
             this.baseClock = baseClock;

@@ -690,10 +691,11 @@
      * Implementation of a clock that adds an offset to an underlying clock.
      */
     static final class TickClock extends Clock implements Serializable {
         @java.io.Serial
         private static final long serialVersionUID = 6504659149906368850L;
+        @SuppressWarnings("serial") // Not statically typed as Serializable
         private final Clock baseClock;
         private final long tickNanos;
 
         TickClock(Clock baseClock, long tickNanos) {
             this.baseClock = baseClock;