--- a/jdk/src/share/classes/java/time/chrono/ChronoZonedDateTime.java	Wed Sep 04 15:18:54 2013 +0100
+++ b/jdk/src/share/classes/java/time/chrono/ChronoZonedDateTime.java	Sat Sep 14 22:46:49 2013 +0100
@@ -166,6 +166,7 @@
         if (temporal instanceof ChronoZonedDateTime) {
             return (ChronoZonedDateTime<?>) temporal;
         }
+        Objects.requireNonNull(temporal, "temporal");
         Chronology chrono = temporal.query(TemporalQuery.chronology());
         if (chrono == null) {
             throw new DateTimeException("Unable to obtain ChronoZonedDateTime from TemporalAccessor: " + temporal.getClass());