diff --git a/doc/setup/deploy.rst b/doc/setup/deploy.rst
index fb372eb63e6..d6ab005bdb3 100644
--- a/doc/setup/deploy.rst
+++ b/doc/setup/deploy.rst
@@ -192,6 +192,10 @@ Instead you must have a proxy redirecting requests whose URL starts with
 ``/longpolling/`` to the longpolling port. Other request should be proxied to
 the :option:`normal HTTP port <odoo.py --xmlrpc-port>`
 
+.. warning:: The livechat worker requires the ``psycogreen`` Python module,
+             which is not always included with all installation packages.
+             It can be manually installed with ``pip install psycogreen``.
+
 Configuration sample
 --------------------
 
diff --git a/openerp/addons/base/base.sql b/openerp/addons/base/base.sql
index a994cc906cc..28219cce13e 100644
--- a/openerp/addons/base/base.sql
+++ b/openerp/addons/base/base.sql
@@ -95,7 +95,7 @@ CREATE TABLE ir_module_module (
     website character varying(256),
     summary character varying(256),
     name character varying(128) NOT NULL,
-    author character varying(128),
+    author character varying,
     icon varchar,
     state character varying(16),
     latest_version character varying(64),