diff --git a/odoo/models.py b/odoo/models.py
index b37fa0fe530..611b2bdbff3 100644
--- a/odoo/models.py
+++ b/odoo/models.py
@@ -1752,7 +1752,8 @@ class BaseModel(object):
                     order = '"%s" %s' % (order_field, '' if len(order_split) == 1 else order_split[1])
                     orderby_terms.append(order)
             elif order_field in aggregated_fields:
-                orderby_terms.append(order_part)
+                order_split[0] = '"' + order_field + '"'
+                orderby_terms.append(' '.join(order_split))
             else:
                 # Cannot order by a field that will not appear in the results (needs to be grouped or aggregated)
                 _logger.warn('%s: read_group order by `%s` ignored, cannot sort on empty columns (not grouped/aggregated)',