diff --git a/inc/CalDAVRequest.php b/inc/CalDAVRequest.php
index 70d9a150..4455472e 100644
--- a/inc/CalDAVRequest.php
+++ b/inc/CalDAVRequest.php
@@ -322,9 +322,9 @@ class CalDAVRequest
       $params[':resourcetypes'] = sprintf('<DAV::collection/><urn:ietf:params:xml:ns:caldav:%s/>', $this->collection_type );
       $sql = <<<EOSQL
 INSERT INTO collection ( user_no, parent_container, dav_name, dav_displayname, is_calendar, created, modified, dav_etag, resourcetypes )
-    VALUES( (SELECT user_no FROM usr WHERE username = :username),
+    VALUES( (SELECT user_no FROM usr WHERE username = text(:username)),
             :parent_container, :dav_name,
-            (SELECT fullname FROM usr WHERE username = :username) || :boxname,
+            (SELECT fullname FROM usr WHERE username = text(:username)) || :boxname,
              FALSE, current_timestamp, current_timestamp, '1', :resourcetypes )
 EOSQL;
 
diff --git a/inc/DAVResource.php b/inc/DAVResource.php
index 93e5cc8e..d50e4c54 100644
--- a/inc/DAVResource.php
+++ b/inc/DAVResource.php
@@ -360,9 +360,9 @@ class DAVResource
       $params[':resourcetypes'] = sprintf('<DAV::collection/><urn:ietf:params:xml:ns:caldav:%s/>', $this->collection_type );
       $sql = <<<EOSQL
 INSERT INTO collection ( user_no, parent_container, dav_name, dav_displayname, is_calendar, created, modified, dav_etag, resourcetypes )
-    VALUES( (SELECT user_no FROM usr WHERE username = :username),
+    VALUES( (SELECT user_no FROM usr WHERE username = text(:username)),
             :parent_container, :dav_name,
-            (SELECT fullname FROM usr WHERE username = :username) || :boxname,
+            (SELECT fullname FROM usr WHERE username = text(:username)) || :boxname,
              FALSE, current_timestamp, current_timestamp, '1', :resourcetypes )
 EOSQL;
       $qry = new AwlQuery( $sql, $params );