diff --git a/src/java.base/share/classes/java/util/Calendar.java b/src/java.base/share/classes/java/util/Calendar.java
index 6d0761191dc..cfcc0750e8b 100644
--- a/src/java.base/share/classes/java/util/Calendar.java
+++ b/src/java.base/share/classes/java/util/Calendar.java
@@ -1632,6 +1632,7 @@ public abstract class Calendar implements Serializable, Cloneable, Comparable<Ca
      *
      * @param zone the time zone to use
      * @return a Calendar.
+     * @throws NullPointerException if {@code zone} is {@code null}
      */
     public static Calendar getInstance(TimeZone zone)
     {
@@ -1649,6 +1650,7 @@ public abstract class Calendar implements Serializable, Cloneable, Comparable<Ca
      *
      * @param aLocale the locale for the week data
      * @return a Calendar.
+     * @throws NullPointerException if {@code aLocale} is {@code null}
      */
     public static Calendar getInstance(Locale aLocale)
     {
@@ -1663,6 +1665,7 @@ public abstract class Calendar implements Serializable, Cloneable, Comparable<Ca
      * @param zone the time zone to use
      * @param aLocale the locale for the week data
      * @return a Calendar.
+     * @throws NullPointerException if {@code zone} or {@code aLocale} is {@code null}
      */
     public static Calendar getInstance(TimeZone zone,
                                        Locale aLocale)
diff --git a/src/java.base/share/classes/java/util/GregorianCalendar.java b/src/java.base/share/classes/java/util/GregorianCalendar.java
index a79baa49a78..d6e559fabfc 100644
--- a/src/java.base/share/classes/java/util/GregorianCalendar.java
+++ b/src/java.base/share/classes/java/util/GregorianCalendar.java
@@ -599,6 +599,7 @@ public class GregorianCalendar extends Calendar {
      * {@link Locale.Category#FORMAT FORMAT} locale.
      *
      * @param zone the given time zone.
+     * @throws NullPointerException if {@code zone} is {@code null}
      */
     public GregorianCalendar(TimeZone zone) {
         this(zone, Locale.getDefault(Locale.Category.FORMAT));
@@ -609,6 +610,7 @@ public class GregorianCalendar extends Calendar {
      * in the default time zone with the given locale.
      *
      * @param aLocale the given locale.
+     * @throws NullPointerException if {@code aLocale} is {@code null}
      */
     public GregorianCalendar(Locale aLocale) {
         this(TimeZone.getDefaultRef(), aLocale);
@@ -621,6 +623,7 @@ public class GregorianCalendar extends Calendar {
      *
      * @param zone the given time zone.
      * @param aLocale the given locale.
+     * @throws NullPointerException if {@code zone} or {@code aLocale} is {@code null}
      */
     public GregorianCalendar(TimeZone zone, Locale aLocale) {
         super(zone, aLocale);