diff --git a/flask_rest_jsonapi/data_layers/alchemy.py b/flask_rest_jsonapi/data_layers/alchemy.py
index f08b2ec..2cf231b 100644
--- a/flask_rest_jsonapi/data_layers/alchemy.py
+++ b/flask_rest_jsonapi/data_layers/alchemy.py
@@ -452,7 +452,12 @@ def sort_query(self, query, sort_info):
             field = sort_opt['field']
             if not hasattr(self.model, field):
                 raise InvalidSort("{} has no attribute {}".format(self.model.__name__, field))
-            query = query.order_by(getattr(getattr(self.model, field), sort_opt['order'])())
+            if sort_opt['relationship']:
+                relationField = getattr(self.model, field)
+                relationClass = relationField.mapper.class_
+                query = query.join(relationField).order_by(getattr(getattr(relationClass, 'id'), sort_opt['order'])())
+            else:
+                query = query.order_by(getattr(getattr(self.model, field), sort_opt['order'])())
         return query
 
     def paginate_query(self, query, paginate_info):
diff --git a/flask_rest_jsonapi/querystring.py b/flask_rest_jsonapi/querystring.py
index 3bfc2b5..6bebbaa 100644
--- a/flask_rest_jsonapi/querystring.py
+++ b/flask_rest_jsonapi/querystring.py
@@ -165,14 +165,16 @@ def sorting(self):
         if self.qs.get('sort'):
             sorting_results = []
             for sort_field in self.qs['sort'].split(','):
+                relationship = False
                 field = sort_field.replace('-', '')
                 if field not in self.schema._declared_fields:
                     raise InvalidSort("{} has no attribute {}".format(self.schema.__name__, field))
                 if field in get_relationships(self.schema):
-                    raise InvalidSort("You can't sort on {} because it is a relationship field".format(field))
+                    #raise InvalidSort("You can't sort on {} because it is a relationship field".format(field))
+                    relationship = True
                 field = get_model_field(self.schema, field)
                 order = 'desc' if sort_field.startswith('-') else 'asc'
-                sorting_results.append({'field': field, 'order': order})
+                sorting_results.append({'field': field, 'order': order, 'relationship': relationship})
             return sorting_results
 
         return []
diff --git a/tests/test_sqlalchemy_data_layer.py b/tests/test_sqlalchemy_data_layer.py
index d5f62a3..11b9202 100644
--- a/tests/test_sqlalchemy_data_layer.py
+++ b/tests/test_sqlalchemy_data_layer.py
@@ -389,9 +389,9 @@ def test_query_string_manager(person_schema):
     qsm = QSManager(query_string, person_schema)
     with pytest.raises(BadRequest):
         qsm.pagination
-    qsm.qs['sort'] = 'computers'
-    with pytest.raises(InvalidSort):
-        qsm.sorting
+    #qsm.qs['sort'] = 'computers'
+    #with pytest.raises(InvalidSort):
+        #qsm.sorting
 
 
 def test_resource(app, person_model, person_schema, session, monkeypatch):
@@ -474,6 +474,46 @@ def test_get_list(client, register_routes, person, person_2):
         response = client.get('/persons' + '?' + querystring, content_type='application/vnd.api+json')
         assert response.status_code == 200
 
+def test_get_list_sort_relationship(client, register_routes, person, person_2):
+    with client:
+        querystring = urlencode({'page[number]': 1,
+                                 'page[size]': 1,
+                                 'fields[person]': 'name,birth_date',
+                                 'sort': '-computers',
+                                 'include': 'computers.owner',
+                                 'filter': json.dumps(
+                                     [
+                                         {
+                                             'and': [
+                                                 {
+                                                     'name': 'computers',
+                                                     'op': 'any',
+                                                     'val': {
+                                                         'name': 'serial',
+                                                         'op': 'eq',
+                                                         'val': '0000'
+                                                     }
+                                                 },
+                                                 {
+                                                     'or': [
+                                                         {
+                                                             'name': 'name',
+                                                             'op': 'like',
+                                                             'val': '%test%'
+                                                         },
+                                                         {
+                                                             'name': 'name',
+                                                             'op': 'like',
+                                                             'val': '%test2%'
+                                                         }
+                                                     ]
+                                                 }
+                                             ]
+                                         }
+                                     ])})
+        response = client.get('/persons' + '?' + querystring, content_type='application/vnd.api+json')
+        assert response.status_code == 200
+
 
 def test_get_list_disable_pagination(client, register_routes):
     with client: