diff --git a/__openerp__.py b/__openerp__.py
index 328da8e6..5c8ac75a 100644
--- a/__openerp__.py
+++ b/__openerp__.py
@@ -39,7 +39,7 @@ The py3o.template package is required; install it with:
         'report'
     ],
     'external_dependencies': {
-        'python': ['py3o.template']
+        'python': ['py3o.template', 'oe_json_serializer']
     },
     'data': [
         'security/ir.model.access.csv',
diff --git a/py3o_report_modif.py b/py3o_report_modif.py
index 0e496efb..84028446 100644
--- a/py3o_report_modif.py
+++ b/py3o_report_modif.py
@@ -83,7 +83,7 @@ class py3o_report(report_sxw):
         #TODO: Find a way to avoid calling Template
         t = Template(in_temp.name, out_temp.name)
         # Remove 'py3o.'
-        user_variable = [x[5:] for x in t.get_user_variable()]
+        user_variable = [x[5:] for x in t.get_user_variables()]
         print user_variable
 
         values = self.get_values(cr, uid, ids, data, context)