diff --git a/inc/DAViCalSession.php b/inc/DAViCalSession.php
index 04b6d5d2..c7635fa5 100644
--- a/inc/DAViCalSession.php
+++ b/inc/DAViCalSession.php
@@ -65,6 +65,14 @@ class DAViCalSession extends Session
   * @param object $u The user+session object we (probably) read from the database.
   */
   function AssignSessionDetails( $u ) {
+    if ( !isset($u->principal_id) ) {
+      // If they don't have a principal_id set then we should re-read from our local database
+      $qry = new AwlQuery('SELECT * FROM dav_principal WHERE username = :username', array(':username' => $u->username) );
+      if ( $qry->Exec() && $qry->rows() == 1 ) {
+        $u = $qry->Fetch();
+      }
+    }
+
     parent::AssignSessionDetails( $u );
     $this->GetRoles();
     if ( function_exists('awl_set_locale') && isset($this->locale) && $this->locale != '' ) {
diff --git a/inc/HTTPAuthSession.php b/inc/HTTPAuthSession.php
index 344530ad..6e8a998c 100644
--- a/inc/HTTPAuthSession.php
+++ b/inc/HTTPAuthSession.php
@@ -274,6 +274,14 @@ class HTTPAuthSession {
   * @param object $u The user+session object we (probably) read from the database.
   */
   function AssignSessionDetails( $u ) {
+    if ( !isset($u->principal_id) ) {
+      // If they don't have a principal_id set then we should re-read from our local database
+      $qry = new AwlQuery('SELECT * FROM dav_principal WHERE username = :username', array(':username' => $u->username) );
+      if ( $qry->Exec() && $qry->rows() == 1 ) {
+        $u = $qry->Fetch();
+      }
+    }
+
     // Assign each field in the selected record to the object
     foreach( $u AS $k => $v ) {
       $this->{$k} = $v;