diff --git a/bin/tools/misc.py b/bin/tools/misc.py
index e552660e3e2..07e0fc38f8e 100644
--- a/bin/tools/misc.py
+++ b/bin/tools/misc.py
@@ -101,7 +101,7 @@ def init_db(cr):
                 values (%s, %s, %s, %s, %s, %s, %s, %s, %s)', (
             id, info.get('author', ''),
             info.get('website', ''), i, info.get('name', False),
-            info.get('description', ''), p_id, state, info.get('certificate')))
+            info.get('description', ''), p_id, state, info.get('certificate') or None))
         cr.execute('insert into ir_model_data \
             (name,model,module, res_id, noupdate) values (%s,%s,%s,%s,%s)', (
                 'module_meta_information', 'ir.module.module', i, id, True))