diff --git a/reference/mongo/mongocollection/ensureindex.xml b/reference/mongo/mongocollection/ensureindex.xml
index 918c2e6b24..c133e82715 100644
--- a/reference/mongo/mongocollection/ensureindex.xml
+++ b/reference/mongo/mongocollection/ensureindex.xml
@@ -154,10 +154,15 @@
second parameter was an optional boolean value specifying a unique
index.
+
+
1.0.11
"safe" will trigger master failover, if necessary.
+
+
+ 1.0.11
MongoException will be thrown if index name
(either generated or set) is longer than 128 bytes.