diff --git a/classes/Notice.php b/classes/Notice.php
index bcd84501ec..71d4d4ff23 100644
--- a/classes/Notice.php
+++ b/classes/Notice.php
@@ -2407,4 +2407,22 @@ class Notice extends Memcached_DataObject
         }
         return $this->_original;
     }
+
+    /**
+     * Magic function called at serialize() time.
+     *
+     * We use this to drop a couple process-specific references
+     * from DB_DataObject which can cause trouble in future
+     * processes.
+     *
+     * @return array of variable names to include in serialization.
+     */
+
+    function __sleep()
+    {
+        $vars = parent::__sleep();
+        $skip = array('_original', '_profile');
+        return array_diff($vars, $skip);
+    }
+
 }
diff --git a/classes/Profile.php b/classes/Profile.php
index 16484fbe6e..2638f745f7 100644
--- a/classes/Profile.php
+++ b/classes/Profile.php
@@ -1353,4 +1353,21 @@ class Profile extends Memcached_DataObject
         }
         return $profile;
     }
+
+    /**
+     * Magic function called at serialize() time.
+     *
+     * We use this to drop a couple process-specific references
+     * from DB_DataObject which can cause trouble in future
+     * processes.
+     *
+     * @return array of variable names to include in serialization.
+     */
+
+    function __sleep()
+    {
+        $vars = parent::__sleep();
+        $skip = array('_user');
+        return array_diff($vars, $skip);
+    }
 }
diff --git a/classes/User.php b/classes/User.php
index d8f813c765..8642c78c27 100644
--- a/classes/User.php
+++ b/classes/User.php
@@ -983,4 +983,21 @@ class User extends Memcached_DataObject
 
         return $apps;
     }
+
+    /**
+     * Magic function called at serialize() time.
+     *
+     * We use this to drop a couple process-specific references
+     * from DB_DataObject which can cause trouble in future
+     * processes.
+     *
+     * @return array of variable names to include in serialization.
+     */
+
+    function __sleep()
+    {
+        $vars = parent::__sleep();
+        $skip = array('_profile');
+        return array_diff($vars, $skip);
+    }
 }