diff --git a/odoo/addons/base/ir/ir_qweb/assetsbundle.py b/odoo/addons/base/ir/ir_qweb/assetsbundle.py
index d6b7705423a..5034c1d84cf 100644
--- a/odoo/addons/base/ir/ir_qweb/assetsbundle.py
+++ b/odoo/addons/base/ir/ir_qweb/assetsbundle.py
@@ -479,7 +479,7 @@ class WebAsset(object):
                 with open(self._filename, 'rb') as fp:
                     return fp.read().decode('utf-8')
             else:
-                return self._ir_attach['datas'].decode('base64')
+                return self._ir_attach['datas'].decode('base64').decode('utf-8')
         except UnicodeDecodeError:
             raise AssetError('%s is not utf-8 encoded.' % self.name)
         except IOError: