diff --git a/openerp/models.py b/openerp/models.py
index 93640f8c3dc..58998067441 100644
--- a/openerp/models.py
+++ b/openerp/models.py
@@ -4595,11 +4595,24 @@ class BaseModel(object):
         """
         lang = self._context.get('lang')
         if lang and lang != 'en_US':
+            # Sub-select to return at most one translation per record.
+            # Even if it shoud probably not be the case,
+            # this is possible to have multiple translations for a same record in the same language.
+            # The parenthesis surrounding the select are important, as this is a sub-select.
+            # The quotes surrounding `ir_translation` are important as well.
+            unique_translation_subselect = """
+            (SELECT DISTINCT ON (res_id) res_id, value
+            FROM "ir_translation"
+            WHERE
+                name = %s AND
+                lang = %s AND
+                value != %s
+            ORDER BY res_id, id DESC)
+            """
             alias, alias_statement = query.add_join(
-                (table_alias, 'ir_translation', 'id', 'res_id', field),
+                (table_alias, unique_translation_subselect, 'id', 'res_id', field),
                 implicit=False,
                 outer=True,
-                extra='"{rhs}"."name" = %s AND "{rhs}"."lang" = %s AND "{rhs}"."value" != %s',
                 extra_params=["%s,%s" % (self._name, field), lang, ""],
             )
             return 'COALESCE("%s"."%s", "%s"."%s")' % (alias, 'value', table_alias, field)
diff --git a/openerp/osv/query.py b/openerp/osv/query.py
index 3fbdc476d4e..5fe53cfdf87 100644
--- a/openerp/osv/query.py
+++ b/openerp/osv/query.py
@@ -132,8 +132,8 @@ class Query(object):
                 self.tables.append(alias_statement)
                 join_tuple = (alias, lhs_col, col, outer and 'LEFT JOIN' or 'JOIN')
                 self.joins.setdefault(lhs, []).append(join_tuple)
-                if extra:
-                    extra = extra.format(lhs=lhs, rhs=alias)
+                if extra or extra_params:
+                    extra = (extra or '').format(lhs=lhs, rhs=alias)
                     self.extras[(lhs, join_tuple)] = (extra, extra_params)
             return alias, alias_statement
 
@@ -152,9 +152,11 @@ class Query(object):
                     (join, alias_mapping[rhs], lhs, lhs_col, rhs, rhs_col))
                 extra = self.extras.get((lhs, (rhs, lhs_col, rhs_col, join)))
                 if extra:
-                    from_clause.append(' AND ')
-                    from_clause.append(extra[0])
-                    from_params.extend(extra[1])
+                    if extra[0]:
+                        from_clause.append(' AND ')
+                        from_clause.append(extra[0])
+                    if extra[1]:
+                        from_params.extend(extra[1])
                 from_clause.append(')')
                 add_joins_for_table(rhs)