diff --git a/calendar/base/public/calIRecurrenceInfo.idl b/calendar/base/public/calIRecurrenceInfo.idl
index 977c0771cec4..394bd1d0259f 100644
--- a/calendar/base/public/calIRecurrenceInfo.idl
+++ b/calendar/base/public/calIRecurrenceInfo.idl
@@ -71,7 +71,7 @@ interface calIRecurrenceInfo : nsISupports
 
   attribute long recurType;
 
-  attribute calIDatetime recurStart;
+  attribute calIDateTime recurStart;
 
   // setting either of these attributes calculates the other.
   // recurCount of -1 or null recurEnd means "forever"