diff --git a/jetty-nosql/src/main/java/org/eclipse/jetty/nosql/mongodb/MongoSessionManager.java b/jetty-nosql/src/main/java/org/eclipse/jetty/nosql/mongodb/MongoSessionManager.java
index 5fb218df2d5..085522f270a 100644
--- a/jetty-nosql/src/main/java/org/eclipse/jetty/nosql/mongodb/MongoSessionManager.java
+++ b/jetty-nosql/src/main/java/org/eclipse/jetty/nosql/mongodb/MongoSessionManager.java
@@ -364,7 +364,7 @@ public class MongoSessionManager extends NoSqlSessionManager
             BasicDBObject remove = new BasicDBObject();
             BasicDBObject unsets = new BasicDBObject();
             unsets.put(getContextKey(),1);
-            remove.put("$unsets",unsets);
+            remove.put("$unset",unsets);
             _sessions.update(key,remove);
 
             return true;