diff --git a/src/main/java/net/fortuna/ical4j/model/Recur.java b/src/main/java/net/fortuna/ical4j/model/Recur.java
index ee746926b..300266ea6 100644
--- a/src/main/java/net/fortuna/ical4j/model/Recur.java
+++ b/src/main/java/net/fortuna/ical4j/model/Recur.java
@@ -206,6 +206,7 @@ private Recur() {
      *
      * @param aValue a string representation of a recurrence.
      * @throws ParseException thrown when the specified string contains an invalid representation of an UNTIL date value
+     * @throws IllegalArgumentException where the recurrence string contains an unrecognised token
      */
     public Recur(final String aValue) throws ParseException {
         // default week start is Monday per RFC5545
diff --git a/src/main/java/net/fortuna/ical4j/model/property/RRule.java b/src/main/java/net/fortuna/ical4j/model/property/RRule.java
index 7eaf8b8e5..534ad14ab 100644
--- a/src/main/java/net/fortuna/ical4j/model/property/RRule.java
+++ b/src/main/java/net/fortuna/ical4j/model/property/RRule.java
@@ -65,7 +65,8 @@ public RRule() {
 
     /**
      * @param value a rule string
-     * @throws ParseException where the specified string is not a valid rule
+     * @throws ParseException where the if the UNTIL part of the recurrence string is an invalid date representation
+     * @throws IllegalArgumentException where the recurrence string contains an unrecognised token
      */
     public RRule(String value) throws ParseException {
         super(RRULE, new Factory());