diff --git a/lib/SimpleSAML/Session.php b/lib/SimpleSAML/Session.php
index de5b4627..bf0b8e0f 100644
--- a/lib/SimpleSAML/Session.php
+++ b/lib/SimpleSAML/Session.php
@@ -98,14 +98,6 @@ class SimpleSAML_Session {
 	private $dataStore = null;
 
 
-	/**
-	 * Current NameIDs for sessions.
-	 *
-	 * Stored as a two-level associative array: $sessionNameId[<entityType>][<entityId>]
-	 */
-	private $sessionNameId;
-
-
 	/**
 	 * The list of IdP-SP associations.
 	 *