diff --git a/classes/Notice.php b/classes/Notice.php
index 9a39c6dc63..2a387d5539 100644
--- a/classes/Notice.php
+++ b/classes/Notice.php
@@ -308,6 +308,9 @@ class Notice extends Managed_DataObject
     }
 
     public function getObjectType($canonical=false) {
+        if (is_null($this->object_type) || $this->object_type==='') {
+            throw new NoObjectTypeException($this);
+        }
         return ActivityUtils::resolveUri($this->object_type, $canonical);
     }
 
diff --git a/lib/noobjecttypeexception.php b/lib/noobjecttypeexception.php
new file mode 100644
index 0000000000..bbeea11204
--- /dev/null
+++ b/lib/noobjecttypeexception.php
@@ -0,0 +1,41 @@
+<?php
+/**
+ * StatusNet, the distributed open-source microblogging tool
+ *
+ * Class for an exception when a database lookup returns no results
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Exception
+ * @package   GNUsocial
+ * @author    Mikael Nordfeldth <mmn@hethane.se>
+ * @copyright 2013 Free Software Foundation, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPLv3
+ * @link      http://www.gnu.org/software/social/
+ */
+
+if (!defined('GNUSOCIAL')) { exit(1); }
+
+class NoObjectTypeException extends ServerException
+{
+    public $stored;    // The object with query that gave no results
+
+    public function __construct(Notice $stored)
+    {
+        $this->stored = $stored;
+        parent::__construct(sprintf(_('Notice has no object type.')));
+    }
+}