diff --git a/taiga/base/models.py b/taiga/base/models.py
index 90d40912..9cb0cd80 100644
--- a/taiga/base/models.py
+++ b/taiga/base/models.py
@@ -14,8 +14,6 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from django.db.models import Q
-
 # Patch api view for correctly return 401 responses on
 # request is authenticated instead of 403
 from . import monkey
diff --git a/taiga/base/utils/json.py b/taiga/base/utils/json.py
index 80bb0bc6..dcb818a3 100644
--- a/taiga/base/utils/json.py
+++ b/taiga/base/utils/json.py
@@ -18,9 +18,14 @@ import json
 from rest_framework.utils import encoders
 
 
-def to_json(data, ensure_ascii=True, encoder_class=encoders.JSONEncoder):
+def dumps(data, ensure_ascii=True, encoder_class=encoders.JSONEncoder):
     return json.dumps(data, cls=encoder_class, indent=None, ensure_ascii=ensure_ascii)
 
 
-def from_json(data):
+def loads(data):
     return json.loads(data)
+
+# Some backward compatibility that should
+# be removed in near future.
+to_json = dumps
+from_json = loads
diff --git a/taiga/projects/attachments/api.py b/taiga/projects/attachments/api.py
index 987a721c..71519bae 100644
--- a/taiga/projects/attachments/api.py
+++ b/taiga/projects/attachments/api.py
@@ -34,7 +34,6 @@ from taiga.users.models import User
 from taiga.projects.notifications import WatchedResourceMixin
 from taiga.projects.history import HistoryResourceMixin
 
-
 from . import permissions
 from . import serializers
 from . import models
@@ -47,6 +46,12 @@ class BaseAttachmentViewSet(HistoryResourceMixin, WatchedResourceMixin, ModelCru
 
     content_type = None
 
+    def update(self, *args, **kwargs):
+        partial = kwargs.get("partial", False)
+        if not partial:
+            raise exc.NotSupported("Non partial updates not supported")
+        return super().update(*args, **kwargs)
+
     def get_content_type(self):
         app_name, model = self.content_type.split(".", 1)
         return get_object_or_404(ContentType, app_label=app_name, model=model)
@@ -56,6 +61,9 @@ class BaseAttachmentViewSet(HistoryResourceMixin, WatchedResourceMixin, ModelCru
             obj.content_type = self.get_content_type()
             obj.owner = self.request.user
 
+        if obj.project_id != obj.content_object.project_id:
+            raise exc.WrongArguments("Project ID not matches between object and project")
+
         super().pre_save(obj)
 
     def post_delete(self, obj):
@@ -72,36 +80,24 @@ class UserStoryAttachmentViewSet(BaseAttachmentViewSet):
     permission_classes = (permissions.UserStoryAttachmentPermission,)
     filter_backends = (filters.CanViewUserStoryAttachmentFilterBackend,)
     content_type = "userstories.userstory"
-    create_notification_template = "create_userstory_notification"
-    update_notification_template = "update_userstory_notification"
-    destroy_notification_template = "destroy_userstory_notification"
 
 
 class IssueAttachmentViewSet(BaseAttachmentViewSet):
     permission_classes = (permissions.IssueAttachmentPermission,)
     filter_backends = (filters.CanViewIssueAttachmentFilterBackend,)
     content_type = "issues.issue"
-    create_notification_template = "create_issue_notification"
-    update_notification_template = "update_issue_notification"
-    destroy_notification_template = "destroy_issue_notification"
 
 
 class TaskAttachmentViewSet(BaseAttachmentViewSet):
     permission_classes = (permissions.TaskAttachmentPermission,)
     filter_backends = (filters.CanViewTaskAttachmentFilterBackend,)
     content_type = "tasks.task"
-    create_notification_template = "create_task_notification"
-    update_notification_template = "update_task_notification"
-    destroy_notification_template = "destroy_task_notification"
 
 
 class WikiAttachmentViewSet(BaseAttachmentViewSet):
     permission_classes = (permissions.WikiAttachmentPermission,)
     filter_backends = (filters.CanViewWikiAttachmentFilterBackend,)
     content_type = "wiki.wikipage"
-    create_notification_template = "create_wiki_notification"
-    update_notification_template = "update_wiki_notification"
-    destroy_notification_template = "destroy_wiki_notification"
 
 
 class RawAttachmentView(generics.RetrieveAPIView):
diff --git a/taiga/projects/attachments/permissions.py b/taiga/projects/attachments/permissions.py
index f5708ca0..47d922aa 100644
--- a/taiga/projects/attachments/permissions.py
+++ b/taiga/projects/attachments/permissions.py
@@ -16,7 +16,7 @@
 
 
 from taiga.base.api.permissions import (TaigaResourcePermission, HasProjectPerm,
-                                        IsProjectOwner, AllowAny, PermissionComponent)
+                                        AllowAny, PermissionComponent)
 
 
 class IsAttachmentOwnerPerm(PermissionComponent):
diff --git a/taiga/projects/attachments/serializers.py b/taiga/projects/attachments/serializers.py
index e772c5e8..46ba0b97 100644
--- a/taiga/projects/attachments/serializers.py
+++ b/taiga/projects/attachments/serializers.py
@@ -21,7 +21,9 @@ from django.conf import settings
 
 from rest_framework import serializers
 
+from taiga.base.serializers import ModelSerializer
 from taiga.base.utils.urls import reverse
+
 from . import models
 
 
@@ -30,6 +32,8 @@ class AttachmentSerializer(serializers.ModelSerializer):
     url = serializers.SerializerMethodField("get_url")
     size = serializers.SerializerMethodField("get_size")
 
+    attached_file = serializers.FileField(required=True)
+
     class Meta:
         model = models.Attachment
         fields = ("id", "project", "owner", "name", "attached_file", "size", "url",
diff --git a/tests/fixtures.py b/tests/fixtures.py
index 75f5134f..02b853bd 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -16,6 +16,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import pytest
+import mock
+import functools
 
 
 class Object:
@@ -27,11 +29,36 @@ def object():
     return Object()
 
 
+class PartialMethodCaller:
+    def __init__(self, obj, **partial_params):
+        self.obj = obj
+        self.partial_params = partial_params
+
+    def __getattr__(self, name):
+        return functools.partial(getattr(self.obj, name), **self.partial_params)
+
+
 @pytest.fixture
 def client():
-    from testclient_extensions import Client
+    from django.test.client import Client
+    from django.test.client import MULTIPART_CONTENT
 
-    return Client()
+    class _Client(Client):
+        def login(self, user=None, backend="django.contrib.auth.backends.ModelBackend", **credentials):
+            if user is None:
+                return super().login(**credentials)
+
+            # This will be changed on django1.7 branch with other location
+            with mock.patch('django.test.client.authenticate') as authenticate:
+                user.backend = backend
+                authenticate.return_value = user
+                return super().login(**credentials)
+
+        @property
+        def json(self):
+            return PartialMethodCaller(obj=self, content_type='application/json;charset="utf-8"')
+
+    return _Client()
 
 
 @pytest.fixture
diff --git a/tests/integration/resources_permissions/test_attachment_resources.py b/tests/integration/resources_permissions/test_attachment_resources.py
index 9c0e14f6..2bdf2e2f 100644
--- a/tests/integration/resources_permissions/test_attachment_resources.py
+++ b/tests/integration/resources_permissions/test_attachment_resources.py
@@ -1,16 +1,19 @@
-import pytest
 from django.core.urlresolvers import reverse
+from django.core.files.uploadedfile import SimpleUploadedFile
+from django.test.client import MULTIPART_CONTENT
 
-from rest_framework.renderers import JSONRenderer
+from taiga.base.utils import json
 
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
 from taiga.projects.attachments.serializers import AttachmentSerializer
 
 from tests import factories as f
-from tests.utils import helper_test_http_method, helper_test_http_method_and_count, disconnect_signals, reconnect_signals
-
-import json
+from tests.utils import helper_test_http_method
+from tests.utils import helper_test_http_method_and_count
+from tests.utils import disconnect_signals
+from tests.utils import reconnect_signals
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -72,11 +75,14 @@ def data():
 def data_us(data):
     m = type("Models", (object,), {})
     m.public_user_story = f.UserStoryFactory(project=data.public_project, ref=1)
-    m.public_user_story_attachment = f.UserStoryAttachmentFactory(project=data.public_project, content_object=m.public_user_story)
+    m.public_user_story_attachment = f.UserStoryAttachmentFactory(project=data.public_project,
+                                                                  content_object=m.public_user_story)
     m.private_user_story1 = f.UserStoryFactory(project=data.private_project1, ref=5)
-    m.private_user_story1_attachment = f.UserStoryAttachmentFactory(project=data.private_project1, content_object=m.private_user_story1)
+    m.private_user_story1_attachment = f.UserStoryAttachmentFactory(project=data.private_project1,
+                                                                    content_object=m.private_user_story1)
     m.private_user_story2 = f.UserStoryFactory(project=data.private_project2, ref=9)
-    m.private_user_story2_attachment = f.UserStoryAttachmentFactory(project=data.private_project2, content_object=m.private_user_story2)
+    m.private_user_story2_attachment = f.UserStoryAttachmentFactory(project=data.private_project2,
+                                                                    content_object=m.private_user_story2)
     return m
 
 @pytest.fixture
@@ -197,9 +203,12 @@ def test_wiki_attachment_retrieve(client, data, data_wiki):
 
 
 def test_user_story_attachment_update(client, data, data_us):
-    public_url = reverse('userstory-attachments-detail', kwargs={"pk": data_us.public_user_story_attachment.pk})
-    private_url1 = reverse('userstory-attachments-detail', kwargs={"pk": data_us.private_user_story1_attachment.pk})
-    private_url2 = reverse('userstory-attachments-detail', kwargs={"pk": data_us.private_user_story2_attachment.pk})
+    public_url = reverse("userstory-attachments-detail",
+                         args=[data_us.public_user_story_attachment.pk])
+    private_url1 = reverse("userstory-attachments-detail",
+                           args=[data_us.private_user_story1_attachment.pk])
+    private_url2 = reverse("userstory-attachments-detail",
+                           args=[data_us.private_user_story2_attachment.pk])
 
     users = [
         None,
@@ -211,14 +220,20 @@ def test_user_story_attachment_update(client, data, data_us):
 
     attachment_data = AttachmentSerializer(data_us.public_user_story_attachment).data
     attachment_data["description"] = "test"
-    attachment_data = JSONRenderer().render(attachment_data)
 
-    results = helper_test_http_method(client, 'put', public_url, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
-    results = helper_test_http_method(client, 'put', private_url1, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
-    results = helper_test_http_method(client, 'put', private_url2, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
+    attachment_data = json.dumps(attachment_data)
+
+    results = helper_test_http_method(client, "put", public_url, attachment_data, users)
+    # assert results == [401, 403, 403, 400, 400]
+    assert results == [405, 405, 405, 405, 405]
+
+    results = helper_test_http_method(client, "put", private_url1, attachment_data, users)
+    # assert results == [401, 403, 403, 400, 400]
+    assert results == [405, 405, 405, 405, 405]
+
+    results = helper_test_http_method(client, "put", private_url2, attachment_data, users)
+    # assert results == [401, 403, 403, 400, 400]
+    assert results == [405, 405, 405, 405, 405]
 
 
 def test_task_attachment_update(client, data, data_task):
@@ -236,14 +251,17 @@ def test_task_attachment_update(client, data, data_task):
 
     attachment_data = AttachmentSerializer(data_task.public_task_attachment).data
     attachment_data["description"] = "test"
-    attachment_data = JSONRenderer().render(attachment_data)
+    attachment_data = json.dumps(attachment_data)
 
     results = helper_test_http_method(client, 'put', public_url, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 403, 403, 200, 200]
     results = helper_test_http_method(client, 'put', private_url1, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 403, 403, 200, 200]
     results = helper_test_http_method(client, 'put', private_url2, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 403, 403, 200, 200]
 
 
 def test_issue_attachment_update(client, data, data_issue):
@@ -261,14 +279,17 @@ def test_issue_attachment_update(client, data, data_issue):
 
     attachment_data = AttachmentSerializer(data_issue.public_issue_attachment).data
     attachment_data["description"] = "test"
-    attachment_data = JSONRenderer().render(attachment_data)
+    attachment_data = json.dumps(attachment_data)
 
     results = helper_test_http_method(client, 'put', public_url, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 403, 403, 200, 200]
     results = helper_test_http_method(client, 'put', private_url1, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 403, 403, 200, 200]
     results = helper_test_http_method(client, 'put', private_url2, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 403, 403, 200, 200]
 
 
 def test_wiki_attachment_update(client, data, data_wiki):
@@ -286,14 +307,17 @@ def test_wiki_attachment_update(client, data, data_wiki):
 
     attachment_data = AttachmentSerializer(data_wiki.public_wiki_attachment).data
     attachment_data["description"] = "test"
-    attachment_data = JSONRenderer().render(attachment_data)
+    attachment_data = json.dumps(attachment_data)
 
     results = helper_test_http_method(client, 'put', public_url, attachment_data, users)
-    assert results == [401, 200, 200, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 200, 200, 200, 200]
     results = helper_test_http_method(client, 'put', private_url1, attachment_data, users)
-    assert results == [401, 200, 200, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 200, 200, 200, 200]
     results = helper_test_http_method(client, 'put', private_url2, attachment_data, users)
-    assert results == [401, 403, 403, 200, 200]
+    assert results == [405, 405, 405, 405, 405]
+    # assert results == [401, 403, 403, 200, 200]
 
 
 def test_user_story_attachment_patch(client, data, data_us):
@@ -310,7 +334,7 @@ def test_user_story_attachment_patch(client, data, data_us):
     ]
 
     attachment_data = {"description": "test"}
-    attachment_data = JSONRenderer().render(attachment_data)
+    attachment_data = json.dumps(attachment_data)
 
     results = helper_test_http_method(client, 'patch', public_url, attachment_data, users)
     assert results == [401, 403, 403, 200, 200]
@@ -334,7 +358,7 @@ def test_task_attachment_patch(client, data, data_task):
     ]
 
     attachment_data = {"description": "test"}
-    attachment_data = JSONRenderer().render(attachment_data)
+    attachment_data = json.dumps(attachment_data)
 
     results = helper_test_http_method(client, 'patch', public_url, attachment_data, users)
     assert results == [401, 403, 403, 200, 200]
@@ -358,7 +382,7 @@ def test_issue_attachment_patch(client, data, data_issue):
     ]
 
     attachment_data = {"description": "test"}
-    attachment_data = JSONRenderer().render(attachment_data)
+    attachment_data = json.dumps(attachment_data)
 
     results = helper_test_http_method(client, 'patch', public_url, attachment_data, users)
     assert results == [401, 403, 403, 200, 200]
@@ -382,7 +406,7 @@ def test_wiki_attachment_patch(client, data, data_wiki):
     ]
 
     attachment_data = {"description": "test"}
-    attachment_data = JSONRenderer().render(attachment_data)
+    attachment_data = json.dumps(attachment_data)
 
     results = helper_test_http_method(client, 'patch', public_url, attachment_data, users)
     assert results == [401, 200, 200, 200, 200]
@@ -482,11 +506,16 @@ def test_user_story_attachment_create(client, data, data_us):
         data.project_owner
     ]
 
-    attachment_data = AttachmentSerializer(data_us.public_user_story_attachment).data
-    attachment_data["id"] = None
-    attachment_data["description"] = "test"
-    attachment_data = JSONRenderer().render(attachment_data)
-    results = helper_test_http_method(client, 'post', url, attachment_data, users)
+    attachment_data = {"description": "test",
+                       "object_id": data_us.public_user_story_attachment.object_id,
+                       "project": data_us.public_user_story_attachment.project_id,
+                       "attached_file": SimpleUploadedFile("test.txt", b"test")}
+
+    _after_each_request_hook = lambda: attachment_data["attached_file"].seek(0)
+
+    results = helper_test_http_method(client, 'post', url, attachment_data, users,
+                                      content_type=MULTIPART_CONTENT,
+                                      after_each_request=_after_each_request_hook)
     assert results == [401, 403, 403, 201, 201]
 
 
@@ -501,11 +530,16 @@ def test_task_attachment_create(client, data, data_task):
         data.project_owner
     ]
 
-    attachment_data = AttachmentSerializer(data_task.public_task_attachment).data
-    attachment_data["id"] = None
-    attachment_data["description"] = "test"
-    attachment_data = JSONRenderer().render(attachment_data)
-    results = helper_test_http_method(client, 'post', url, attachment_data, users)
+    attachment_data = {"description": "test",
+                       "object_id": data_task.public_task_attachment.object_id,
+                       "project": data_task.public_task_attachment.project_id,
+                       "attached_file": SimpleUploadedFile("test.txt", b"test")}
+
+    _after_each_request_hook = lambda: attachment_data["attached_file"].seek(0)
+
+    results = helper_test_http_method(client, 'post', url, attachment_data, users,
+                                      content_type=MULTIPART_CONTENT,
+                                      after_each_request=_after_each_request_hook)
     assert results == [401, 403, 403, 201, 201]
 
 
@@ -520,11 +554,17 @@ def test_issue_attachment_create(client, data, data_issue):
         data.project_owner
     ]
 
-    attachment_data = AttachmentSerializer(data_issue.public_issue_attachment).data
-    attachment_data["id"] = None
-    attachment_data["description"] = "test"
-    attachment_data = JSONRenderer().render(attachment_data)
-    results = helper_test_http_method(client, 'post', url, attachment_data, users)
+    attachment_data = {"description": "test",
+                       "object_id": data_issue.public_issue_attachment.object_id,
+                       "project": data_issue.public_issue_attachment.project_id,
+                       "attached_file": SimpleUploadedFile("test.txt", b"test")}
+
+    _after_each_request_hook = lambda: attachment_data["attached_file"].seek(0)
+
+    results = helper_test_http_method(client, 'post', url, attachment_data, users,
+                                      content_type=MULTIPART_CONTENT,
+                                      after_each_request=_after_each_request_hook)
+
     assert results == [401, 403, 403, 201, 201]
 
 
@@ -539,11 +579,17 @@ def test_wiki_attachment_create(client, data, data_wiki):
         data.project_owner
     ]
 
-    attachment_data = AttachmentSerializer(data_wiki.public_wiki_attachment).data
-    attachment_data["id"] = None
-    attachment_data["description"] = "test"
-    attachment_data = JSONRenderer().render(attachment_data)
-    results = helper_test_http_method(client, 'post', url, attachment_data, users)
+    attachment_data = {"description": "test",
+                       "object_id": data_wiki.public_wiki_attachment.object_id,
+                       "project": data_wiki.public_wiki_attachment.project_id,
+                       "attached_file": SimpleUploadedFile("test.txt", b"test")}
+
+    _after_each_request_hook = lambda: attachment_data["attached_file"].seek(0)
+
+    results = helper_test_http_method(client, 'post', url, attachment_data, users,
+                                      content_type=MULTIPART_CONTENT,
+                                      after_each_request=_after_each_request_hook)
+
     assert results == [401, 201, 201, 201, 201]
 
 
diff --git a/tests/integration/resources_permissions/test_auth_resources.py b/tests/integration/resources_permissions/test_auth_resources.py
index 296fb964..8f51080a 100644
--- a/tests/integration/resources_permissions/test_auth_resources.py
+++ b/tests/integration/resources_permissions/test_auth_resources.py
@@ -1,15 +1,12 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
+from taiga.base.utils import json
 
 from tests import factories as f
-from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
-
-import json
+from tests.utils import disconnect_signals, reconnect_signals
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
diff --git a/tests/integration/resources_permissions/test_history_resources.py b/tests/integration/resources_permissions/test_history_resources.py
index 81932926..7cf1950c 100644
--- a/tests/integration/resources_permissions/test_history_resources.py
+++ b/tests/integration/resources_permissions/test_history_resources.py
@@ -1,15 +1,11 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
diff --git a/tests/integration/resources_permissions/test_issues_resources.py b/tests/integration/resources_permissions/test_issues_resources.py
index b5de0869..2bf40ebf 100644
--- a/tests/integration/resources_permissions/test_issues_resources.py
+++ b/tests/integration/resources_permissions/test_issues_resources.py
@@ -1,17 +1,14 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
 from taiga.projects.issues.serializers import IssueSerializer
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
+from taiga.base.utils import json
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
 from taiga.projects.votes.services import add_vote
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -125,19 +122,19 @@ def test_issue_update(client, data):
 
     issue_data = IssueSerializer(data.public_issue).data
     issue_data["subject"] = "test"
-    issue_data = JSONRenderer().render(issue_data)
+    issue_data = json.dumps(issue_data)
     results = helper_test_http_method(client, 'put', public_url, issue_data, users)
     assert results == [401, 403, 403, 200, 200]
 
     issue_data = IssueSerializer(data.private_issue1).data
     issue_data["subject"] = "test"
-    issue_data = JSONRenderer().render(issue_data)
+    issue_data = json.dumps(issue_data)
     results = helper_test_http_method(client, 'put', private_url1, issue_data, users)
     assert results == [401, 403, 403, 200, 200]
 
     issue_data = IssueSerializer(data.private_issue2).data
     issue_data["subject"] = "test"
-    issue_data = JSONRenderer().render(issue_data)
+    issue_data = json.dumps(issue_data)
     results = helper_test_http_method(client, 'put', private_url2, issue_data, users)
     assert results == [401, 403, 403, 200, 200]
 
@@ -295,15 +292,18 @@ def test_issue_bulk_create(client, data):
     ]
 
 
-    bulk_data = json.dumps({"bulk_issues": "test1\ntest2", "project_id": data.public_issue.project.pk})
+    bulk_data = json.dumps({"bulk_issues": "test1\ntest2",
+                            "project_id": data.public_issue.project.pk})
     results = helper_test_http_method(client, 'post', url, bulk_data, users)
     assert results == [401, 200, 200, 200, 200]
 
-    bulk_data = json.dumps({"bulk_issues": "test1\ntest2", "project_id": data.private_issue1.project.pk})
+    bulk_data = json.dumps({"bulk_issues": "test1\ntest2",
+                            "project_id": data.private_issue1.project.pk})
     results = helper_test_http_method(client, 'post', url, bulk_data, users)
     assert results == [401, 200, 200, 200, 200]
 
-    bulk_data = json.dumps({"bulk_issues": "test1\ntest2", "project_id": data.private_issue2.project.pk})
+    bulk_data = json.dumps({"bulk_issues": "test1\ntest2",
+                            "project_id": data.private_issue2.project.pk})
     results = helper_test_http_method(client, 'post', url, bulk_data, users)
     assert results == [401, 403, 403, 200, 200]
 
diff --git a/tests/integration/resources_permissions/test_milestones_resources.py b/tests/integration/resources_permissions/test_milestones_resources.py
index 6f5c1957..8c660968 100644
--- a/tests/integration/resources_permissions/test_milestones_resources.py
+++ b/tests/integration/resources_permissions/test_milestones_resources.py
@@ -1,8 +1,6 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
+from taiga.base.utils import json
 from taiga.projects.milestones.serializers import MilestoneSerializer
 from taiga.projects.milestones.models import Milestone
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
@@ -10,8 +8,7 @@ from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS,
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -110,19 +107,19 @@ def test_milestone_update(client, data):
 
     milestone_data = MilestoneSerializer(data.public_milestone).data
     milestone_data["name"] = "test"
-    milestone_data = JSONRenderer().render(milestone_data)
+    milestone_data = json.dumps(milestone_data)
     results = helper_test_http_method(client, 'put', public_url, milestone_data, users)
     assert results == [401, 403, 403, 200, 200]
 
     milestone_data = MilestoneSerializer(data.private_milestone1).data
     milestone_data["name"] = "test"
-    milestone_data = JSONRenderer().render(milestone_data)
+    milestone_data = json.dumps(milestone_data)
     results = helper_test_http_method(client, 'put', private_url1, milestone_data, users)
     assert results == [401, 403, 403, 200, 200]
 
     milestone_data = MilestoneSerializer(data.private_milestone2).data
     milestone_data["name"] = "test"
-    milestone_data = JSONRenderer().render(milestone_data)
+    milestone_data = json.dumps(milestone_data)
     results = helper_test_http_method(client, 'put', private_url2, milestone_data, users)
     assert results == [401, 403, 403, 200, 200]
 
@@ -240,6 +237,7 @@ def test_milestone_patch(client, data):
     results = helper_test_http_method(client, 'patch', private_url2, patch_data, users)
     assert results == [401, 403, 403, 200, 200]
 
+
 def test_milestone_action_stats(client, data):
     public_url = reverse('milestones-stats', kwargs={"pk": data.public_milestone.pk})
     private_url1 = reverse('milestones-stats', kwargs={"pk": data.private_milestone1.pk})
diff --git a/tests/integration/resources_permissions/test_projects_choices_resources.py b/tests/integration/resources_permissions/test_projects_choices_resources.py
index bdf4beba..8f52124b 100644
--- a/tests/integration/resources_permissions/test_projects_choices_resources.py
+++ b/tests/integration/resources_permissions/test_projects_choices_resources.py
@@ -1,16 +1,13 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
+from taiga.base.utils import json
 from taiga.projects import serializers
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -132,19 +129,19 @@ def test_roles_update(client, data):
 
     role_data = serializers.RoleSerializer(data.public_project.roles.all()[0]).data
     role_data["name"] = "test"
-    role_data = JSONRenderer().render(role_data)
+    role_data = json.dumps(role_data)
     results = helper_test_http_method(client, 'put', public_url, role_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     role_data = serializers.RoleSerializer(data.private_project1.roles.all()[0]).data
     role_data["name"] = "test"
-    role_data = JSONRenderer().render(role_data)
+    role_data = json.dumps(role_data)
     results = helper_test_http_method(client, 'put', private1_url, role_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     role_data = serializers.RoleSerializer(data.private_project2.roles.all()[0]).data
     role_data["name"] = "test"
-    role_data = JSONRenderer().render(role_data)
+    role_data = json.dumps(role_data)
     results = helper_test_http_method(client, 'put', private2_url, role_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -260,19 +257,19 @@ def test_points_update(client, data):
 
     points_data = serializers.PointsSerializer(data.public_points).data
     points_data["name"] = "test"
-    points_data = JSONRenderer().render(points_data)
+    points_data = json.dumps(points_data)
     results = helper_test_http_method(client, 'put', public_url, points_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     points_data = serializers.PointsSerializer(data.private_points1).data
     points_data["name"] = "test"
-    points_data = JSONRenderer().render(points_data)
+    points_data = json.dumps(points_data)
     results = helper_test_http_method(client, 'put', private1_url, points_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     points_data = serializers.PointsSerializer(data.private_points2).data
     points_data["name"] = "test"
-    points_data = JSONRenderer().render(points_data)
+    points_data = json.dumps(points_data)
     results = helper_test_http_method(client, 'put', private2_url, points_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -421,19 +418,19 @@ def test_user_story_status_update(client, data):
 
     user_story_status_data = serializers.UserStoryStatusSerializer(data.public_user_story_status).data
     user_story_status_data["name"] = "test"
-    user_story_status_data = JSONRenderer().render(user_story_status_data)
+    user_story_status_data = json.dumps(user_story_status_data)
     results = helper_test_http_method(client, 'put', public_url, user_story_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     user_story_status_data = serializers.UserStoryStatusSerializer(data.private_user_story_status1).data
     user_story_status_data["name"] = "test"
-    user_story_status_data = JSONRenderer().render(user_story_status_data)
+    user_story_status_data = json.dumps(user_story_status_data)
     results = helper_test_http_method(client, 'put', private1_url, user_story_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     user_story_status_data = serializers.UserStoryStatusSerializer(data.private_user_story_status2).data
     user_story_status_data["name"] = "test"
-    user_story_status_data = JSONRenderer().render(user_story_status_data)
+    user_story_status_data = json.dumps(user_story_status_data)
     results = helper_test_http_method(client, 'put', private2_url, user_story_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -582,19 +579,19 @@ def test_task_status_update(client, data):
 
     task_status_data = serializers.TaskStatusSerializer(data.public_task_status).data
     task_status_data["name"] = "test"
-    task_status_data = JSONRenderer().render(task_status_data)
+    task_status_data = json.dumps(task_status_data)
     results = helper_test_http_method(client, 'put', public_url, task_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     task_status_data = serializers.TaskStatusSerializer(data.private_task_status1).data
     task_status_data["name"] = "test"
-    task_status_data = JSONRenderer().render(task_status_data)
+    task_status_data = json.dumps(task_status_data)
     results = helper_test_http_method(client, 'put', private1_url, task_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     task_status_data = serializers.TaskStatusSerializer(data.private_task_status2).data
     task_status_data["name"] = "test"
-    task_status_data = JSONRenderer().render(task_status_data)
+    task_status_data = json.dumps(task_status_data)
     results = helper_test_http_method(client, 'put', private2_url, task_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -743,19 +740,19 @@ def test_issue_status_update(client, data):
 
     issue_status_data = serializers.IssueStatusSerializer(data.public_issue_status).data
     issue_status_data["name"] = "test"
-    issue_status_data = JSONRenderer().render(issue_status_data)
+    issue_status_data = json.dumps(issue_status_data)
     results = helper_test_http_method(client, 'put', public_url, issue_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     issue_status_data = serializers.IssueStatusSerializer(data.private_issue_status1).data
     issue_status_data["name"] = "test"
-    issue_status_data = JSONRenderer().render(issue_status_data)
+    issue_status_data = json.dumps(issue_status_data)
     results = helper_test_http_method(client, 'put', private1_url, issue_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     issue_status_data = serializers.IssueStatusSerializer(data.private_issue_status2).data
     issue_status_data["name"] = "test"
-    issue_status_data = JSONRenderer().render(issue_status_data)
+    issue_status_data = json.dumps(issue_status_data)
     results = helper_test_http_method(client, 'put', private2_url, issue_status_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -904,19 +901,19 @@ def test_issue_type_update(client, data):
 
     issue_type_data = serializers.IssueTypeSerializer(data.public_issue_type).data
     issue_type_data["name"] = "test"
-    issue_type_data = JSONRenderer().render(issue_type_data)
+    issue_type_data = json.dumps(issue_type_data)
     results = helper_test_http_method(client, 'put', public_url, issue_type_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     issue_type_data = serializers.IssueTypeSerializer(data.private_issue_type1).data
     issue_type_data["name"] = "test"
-    issue_type_data = JSONRenderer().render(issue_type_data)
+    issue_type_data = json.dumps(issue_type_data)
     results = helper_test_http_method(client, 'put', private1_url, issue_type_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     issue_type_data = serializers.IssueTypeSerializer(data.private_issue_type2).data
     issue_type_data["name"] = "test"
-    issue_type_data = JSONRenderer().render(issue_type_data)
+    issue_type_data = json.dumps(issue_type_data)
     results = helper_test_http_method(client, 'put', private2_url, issue_type_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -1065,19 +1062,19 @@ def test_priority_update(client, data):
 
     priority_data = serializers.PrioritySerializer(data.public_priority).data
     priority_data["name"] = "test"
-    priority_data = JSONRenderer().render(priority_data)
+    priority_data = json.dumps(priority_data)
     results = helper_test_http_method(client, 'put', public_url, priority_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     priority_data = serializers.PrioritySerializer(data.private_priority1).data
     priority_data["name"] = "test"
-    priority_data = JSONRenderer().render(priority_data)
+    priority_data = json.dumps(priority_data)
     results = helper_test_http_method(client, 'put', private1_url, priority_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     priority_data = serializers.PrioritySerializer(data.private_priority2).data
     priority_data["name"] = "test"
-    priority_data = JSONRenderer().render(priority_data)
+    priority_data = json.dumps(priority_data)
     results = helper_test_http_method(client, 'put', private2_url, priority_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -1226,19 +1223,19 @@ def test_severity_update(client, data):
 
     severity_data = serializers.SeveritySerializer(data.public_severity).data
     severity_data["name"] = "test"
-    severity_data = JSONRenderer().render(severity_data)
+    severity_data = json.dumps(severity_data)
     results = helper_test_http_method(client, 'put', public_url, severity_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     severity_data = serializers.SeveritySerializer(data.private_severity1).data
     severity_data["name"] = "test"
-    severity_data = JSONRenderer().render(severity_data)
+    severity_data = json.dumps(severity_data)
     results = helper_test_http_method(client, 'put', private1_url, severity_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     severity_data = serializers.SeveritySerializer(data.private_severity2).data
     severity_data["name"] = "test"
-    severity_data = JSONRenderer().render(severity_data)
+    severity_data = json.dumps(severity_data)
     results = helper_test_http_method(client, 'put', private2_url, severity_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -1387,19 +1384,19 @@ def test_membership_update(client, data):
 
     membership_data = serializers.MembershipSerializer(data.public_membership).data
     membership_data["token"] = "test"
-    membership_data = JSONRenderer().render(membership_data)
+    membership_data = json.dumps(membership_data)
     results = helper_test_http_method(client, 'put', public_url, membership_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     membership_data = serializers.MembershipSerializer(data.private_membership1).data
     membership_data["token"] = "test"
-    membership_data = JSONRenderer().render(membership_data)
+    membership_data = json.dumps(membership_data)
     results = helper_test_http_method(client, 'put', private1_url, membership_data, users)
     assert results == [401, 403, 403, 403, 200]
 
     membership_data = serializers.MembershipSerializer(data.private_membership2).data
     membership_data["token"] = "test"
-    membership_data = JSONRenderer().render(membership_data)
+    membership_data = json.dumps(membership_data)
     results = helper_test_http_method(client, 'put', private2_url, membership_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -1492,21 +1489,21 @@ def test_membership_create(client, data):
     membership_data = serializers.MembershipSerializer(data.public_membership).data
     membership_data["id"] = None
     membership_data["email"] = "test1@test.com"
-    membership_data = JSONRenderer().render(membership_data)
+    membership_data = json.dumps(membership_data)
     results = helper_test_http_method(client, 'post', url, membership_data, users)
     assert results == [401, 403, 403, 403, 201]
 
     membership_data = serializers.MembershipSerializer(data.private_membership1).data
     membership_data["id"] = None
     membership_data["email"] = "test2@test.com"
-    membership_data = JSONRenderer().render(membership_data)
+    membership_data = json.dumps(membership_data)
     results = helper_test_http_method(client, 'post', url, membership_data, users)
     assert results == [401, 403, 403, 403, 201]
 
     membership_data = serializers.MembershipSerializer(data.private_membership2).data
     membership_data["id"] = None
     membership_data["email"] = "test3@test.com"
-    membership_data = JSONRenderer().render(membership_data)
+    membership_data = json.dumps(membership_data)
     results = helper_test_http_method(client, 'post', url, membership_data, users)
     assert results == [401, 403, 403, 403, 201]
 
@@ -1529,7 +1526,7 @@ def test_membership_action_bulk_create(client, data):
             {"role_id": data.public_membership.role.pk, "email": "test2@test.com"},
         ]
     }
-    bulk_data = JSONRenderer().render(bulk_data)
+    bulk_data = json.dumps(bulk_data)
     results = helper_test_http_method(client, 'post', url, bulk_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -1540,7 +1537,7 @@ def test_membership_action_bulk_create(client, data):
             {"role_id": data.private_membership1.role.pk, "email": "test2@test.com"},
         ]
     }
-    bulk_data = JSONRenderer().render(bulk_data)
+    bulk_data = json.dumps(bulk_data)
     results = helper_test_http_method(client, 'post', url, bulk_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -1551,7 +1548,7 @@ def test_membership_action_bulk_create(client, data):
             {"role_id": data.private_membership2.role.pk, "email": "test2@test.com"},
         ]
     }
-    bulk_data = JSONRenderer().render(bulk_data)
+    bulk_data = json.dumps(bulk_data)
     results = helper_test_http_method(client, 'post', url, bulk_data, users)
     assert results == [401, 403, 403, 403, 200]
 
@@ -1607,7 +1604,7 @@ def test_project_template_update(client, data):
 
     project_template_data = serializers.ProjectTemplateSerializer(data.project_template).data
     project_template_data["default_owner_role"] = "test"
-    project_template_data = JSONRenderer().render(project_template_data)
+    project_template_data = json.dumps(project_template_data)
     results = helper_test_http_method(client, 'put', url, project_template_data, users)
     assert results == [401, 403, 200]
 
@@ -1657,9 +1654,3 @@ def test_project_template_patch(client, data):
 
     results = helper_test_http_method(client, 'patch', url, '{"name": "Test"}', users)
     assert results == [401, 403, 200]
-
-
-# def test_project_template_action_create_from_project(client, data):
-#     assert False
-#
-#
diff --git a/tests/integration/resources_permissions/test_projects_resource.py b/tests/integration/resources_permissions/test_projects_resource.py
index bc91ed74..02fbe5fd 100644
--- a/tests/integration/resources_permissions/test_projects_resource.py
+++ b/tests/integration/resources_permissions/test_projects_resource.py
@@ -1,17 +1,14 @@
-import pytest
 from django.core.urlresolvers import reverse
 from django.db.models.loading import get_model
 
-from rest_framework.renderers import JSONRenderer
-
+from taiga.base.utils import json
 from taiga.projects.serializers import ProjectDetailSerializer
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, helper_test_http_method_and_count
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -100,7 +97,7 @@ def test_project_update(client, data):
 
     project_data = ProjectDetailSerializer(data.private_project2).data
     project_data["is_private"] = False
-    project_data = JSONRenderer().render(project_data)
+    project_data = json.dumps(project_data)
 
     users = [
         None,
diff --git a/tests/integration/resources_permissions/test_resolver_resources.py b/tests/integration/resources_permissions/test_resolver_resources.py
index fb744731..096c61bb 100644
--- a/tests/integration/resources_permissions/test_resolver_resources.py
+++ b/tests/integration/resources_permissions/test_resolver_resources.py
@@ -1,15 +1,12 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
+from taiga.base.utils import json
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
diff --git a/tests/integration/resources_permissions/test_search_resources.py b/tests/integration/resources_permissions/test_search_resources.py
index fd4f400b..0867675e 100644
--- a/tests/integration/resources_permissions/test_search_resources.py
+++ b/tests/integration/resources_permissions/test_search_resources.py
@@ -1,17 +1,12 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
 from taiga.projects.issues.serializers import IssueSerializer
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method_and_keys, disconnect_signals, reconnect_signals
-from taiga.projects.votes.services import add_vote
-
-import json
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
diff --git a/tests/integration/resources_permissions/test_storage_resources.py b/tests/integration/resources_permissions/test_storage_resources.py
index 47182e8a..8f7f1f05 100644
--- a/tests/integration/resources_permissions/test_storage_resources.py
+++ b/tests/integration/resources_permissions/test_storage_resources.py
@@ -1,19 +1,17 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
-from taiga.userstorage.serializers import StorageEntrySerializer
+from taiga.base.utils import json
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
-
-from tests import factories as f
-from tests.utils import helper_test_http_method, helper_test_http_method_and_count, disconnect_signals, reconnect_signals
 from taiga.projects.votes.services import add_vote
-
+from taiga.userstorage.serializers import StorageEntrySerializer
 from taiga.userstorage.models import StorageEntry
 
-import json
+from tests import factories as f
+from tests.utils import helper_test_http_method
+from tests.utils import helper_test_http_method_and_count
+from tests.utils import disconnect_signals, reconnect_signals
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -63,7 +61,7 @@ def test_storage_update(client, data):
 
     storage_data = StorageEntrySerializer(data.storage_user1).data
     storage_data["key"] = "test"
-    storage_data = JSONRenderer().render(storage_data)
+    storage_data = json.dumps(storage_data)
     results = helper_test_http_method(client, 'put', url, storage_data, users)
     assert results == [401, 200, 201]
 
diff --git a/tests/integration/resources_permissions/test_tasks_resources.py b/tests/integration/resources_permissions/test_tasks_resources.py
index 8da1cafb..bc3f8768 100644
--- a/tests/integration/resources_permissions/test_tasks_resources.py
+++ b/tests/integration/resources_permissions/test_tasks_resources.py
@@ -1,16 +1,13 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
+from taiga.base.utils import json
 from taiga.projects.tasks.serializers import TaskSerializer
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -125,19 +122,19 @@ def test_task_update(client, data):
 
     task_data = TaskSerializer(data.public_task).data
     task_data["subject"] = "test"
-    task_data = JSONRenderer().render(task_data)
+    task_data = json.dumps(task_data)
     results = helper_test_http_method(client, 'put', public_url, task_data, users)
     assert results == [401, 403, 403, 200, 200]
 
     task_data = TaskSerializer(data.private_task1).data
     task_data["subject"] = "test"
-    task_data = JSONRenderer().render(task_data)
+    task_data = json.dumps(task_data)
     results = helper_test_http_method(client, 'put', private_url1, task_data, users)
     assert results == [401, 403, 403, 200, 200]
 
     task_data = TaskSerializer(data.private_task2).data
     task_data["subject"] = "test"
-    task_data = JSONRenderer().render(task_data)
+    task_data = json.dumps(task_data)
     results = helper_test_http_method(client, 'put', private_url2, task_data, users)
     assert results == [401, 403, 403, 200, 200]
 
diff --git a/tests/integration/resources_permissions/test_timelines_resources.py b/tests/integration/resources_permissions/test_timelines_resources.py
index 2dbe7074..c364b0a7 100644
--- a/tests/integration/resources_permissions/test_timelines_resources.py
+++ b/tests/integration/resources_permissions/test_timelines_resources.py
@@ -1,15 +1,11 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
diff --git a/tests/integration/resources_permissions/test_users_resources.py b/tests/integration/resources_permissions/test_users_resources.py
index 4e04f2e4..d3eea37a 100644
--- a/tests/integration/resources_permissions/test_users_resources.py
+++ b/tests/integration/resources_permissions/test_users_resources.py
@@ -1,17 +1,14 @@
-import pytest
+from tempfile import NamedTemporaryFile
+
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
+from taiga.base.utils import json
 from taiga.users.serializers import UserSerializer
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
 
-import json
-
-from tempfile import NamedTemporaryFile
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 DUMMY_BMP_DATA = b'BM:\x00\x00\x00\x00\x00\x00\x006\x00\x00\x00(\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x01\x00\x18\x00\x00\x00\x00\x00\x04\x00\x00\x00\x13\x0b\x00\x00\x13\x0b\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
@@ -62,7 +59,7 @@ def test_user_update(client, data):
 
     user_data = UserSerializer(data.registered_user).data
     user_data["full_name"] = "test"
-    user_data = JSONRenderer().render(user_data)
+    user_data = json.dumps(user_data)
     results = helper_test_http_method(client, 'put', url, user_data, users)
     assert results == [401, 200, 403, 200]
 
diff --git a/tests/integration/resources_permissions/test_userstories_resources.py b/tests/integration/resources_permissions/test_userstories_resources.py
index 4da129df..7be4958b 100644
--- a/tests/integration/resources_permissions/test_userstories_resources.py
+++ b/tests/integration/resources_permissions/test_userstories_resources.py
@@ -1,16 +1,13 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
+from taiga.base.utils import json
 from taiga.projects.userstories.serializers import UserStorySerializer
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
 
-import json
-
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -123,19 +120,19 @@ def test_user_story_update(client, data):
 
     user_story_data = UserStorySerializer(data.public_user_story).data
     user_story_data["subject"] = "test"
-    user_story_data = JSONRenderer().render(user_story_data)
+    user_story_data = json.dumps(user_story_data)
     results = helper_test_http_method(client, 'put', public_url, user_story_data, users)
     assert results == [401, 403, 403, 200, 200]
 
     user_story_data = UserStorySerializer(data.private_user_story1).data
     user_story_data["subject"] = "test"
-    user_story_data = JSONRenderer().render(user_story_data)
+    user_story_data = json.dumps(user_story_data)
     results = helper_test_http_method(client, 'put', private_url1, user_story_data, users)
     assert results == [401, 403, 403, 200, 200]
 
     user_story_data = UserStorySerializer(data.private_user_story2).data
     user_story_data["subject"] = "test"
-    user_story_data = JSONRenderer().render(user_story_data)
+    user_story_data = json.dumps(user_story_data)
     results = helper_test_http_method(client, 'put', private_url2, user_story_data, users)
     assert results == [401, 403, 403, 200, 200]
 
diff --git a/tests/integration/resources_permissions/test_wiki_resources.py b/tests/integration/resources_permissions/test_wiki_resources.py
index 1ee4b580..0691f775 100644
--- a/tests/integration/resources_permissions/test_wiki_resources.py
+++ b/tests/integration/resources_permissions/test_wiki_resources.py
@@ -1,18 +1,14 @@
-import pytest
 from django.core.urlresolvers import reverse
 
-from rest_framework.renderers import JSONRenderer
-
+from taiga.base.utils import json
 from taiga.projects.wiki.serializers import WikiPageSerializer, WikiLinkSerializer
 from taiga.projects.wiki.models import WikiPage, WikiLink
 from taiga.permissions.permissions import MEMBERS_PERMISSIONS, ANON_PERMISSIONS, USER_PERMISSIONS
 
 from tests import factories as f
 from tests.utils import helper_test_http_method, disconnect_signals, reconnect_signals
-from taiga.projects.votes.services import add_vote
-
-import json
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -115,19 +111,19 @@ def test_wiki_page_update(client, data):
 
     wiki_page_data = WikiPageSerializer(data.public_wiki_page).data
     wiki_page_data["content"] = "test"
-    wiki_page_data = JSONRenderer().render(wiki_page_data)
+    wiki_page_data = json.dumps(wiki_page_data)
     results = helper_test_http_method(client, 'put', public_url, wiki_page_data, users)
     assert results == [401, 200, 200, 200, 200]
 
     wiki_page_data = WikiPageSerializer(data.private_wiki_page1).data
     wiki_page_data["content"] = "test"
-    wiki_page_data = JSONRenderer().render(wiki_page_data)
+    wiki_page_data = json.dumps(wiki_page_data)
     results = helper_test_http_method(client, 'put', private_url1, wiki_page_data, users)
     assert results == [401, 200, 200, 200, 200]
 
     wiki_page_data = WikiPageSerializer(data.private_wiki_page2).data
     wiki_page_data["content"] = "test"
-    wiki_page_data = JSONRenderer().render(wiki_page_data)
+    wiki_page_data = json.dumps(wiki_page_data)
     results = helper_test_http_method(client, 'put', private_url2, wiki_page_data, users)
     assert results == [401, 403, 403, 200, 200]
 
@@ -294,19 +290,19 @@ def test_wiki_link_update(client, data):
 
     wiki_link_data = WikiLinkSerializer(data.public_wiki_link).data
     wiki_link_data["title"] = "test"
-    wiki_link_data = JSONRenderer().render(wiki_link_data)
+    wiki_link_data = json.dumps(wiki_link_data)
     results = helper_test_http_method(client, 'put', public_url, wiki_link_data, users)
     assert results == [401, 200, 200, 200, 200]
 
     wiki_link_data = WikiLinkSerializer(data.private_wiki_link1).data
     wiki_link_data["title"] = "test"
-    wiki_link_data = JSONRenderer().render(wiki_link_data)
+    wiki_link_data = json.dumps(wiki_link_data)
     results = helper_test_http_method(client, 'put', private_url1, wiki_link_data, users)
     assert results == [401, 200, 200, 200, 200]
 
     wiki_link_data = WikiLinkSerializer(data.private_wiki_link2).data
     wiki_link_data["title"] = "test"
-    wiki_link_data = JSONRenderer().render(wiki_link_data)
+    wiki_link_data = json.dumps(wiki_link_data)
     results = helper_test_http_method(client, 'put', private_url2, wiki_link_data, users)
     assert results == [401, 403, 403, 200, 200]
 
diff --git a/tests/integration/test_attachments.py b/tests/integration/test_attachments.py
index 72d8ff17..3c498101 100644
--- a/tests/integration/test_attachments.py
+++ b/tests/integration/test_attachments.py
@@ -2,12 +2,16 @@ import pytest
 
 from django.core.urlresolvers import reverse
 from django.core.files.base import File
+from django.core.files.uploadedfile import SimpleUploadedFile
 
 from .. import factories as f
 from ..utils import set_settings
 
+from taiga.projects.attachments.serializers import AttachmentSerializer
+
 pytestmark = pytest.mark.django_db
 
+
 def test_authentication(client):
     "User can't access an attachment if not authenticated"
     attachment = f.UserStoryAttachmentFactory.create()
@@ -56,3 +60,39 @@ def test_attachment_redirect(client):
 
     assert response.status_code == 200
     assert response.has_header('x-accel-redirect')
+
+
+# Bug test "Don't create attachments without attached_file"
+def test_create_user_story_attachment_without_file(client):
+    us = f.UserStoryFactory.create()
+    attachment = f.UserStoryAttachmentFactory(project=us.project, content_object=us)
+
+    attachment_data = AttachmentSerializer(attachment).data
+    attachment_data["id"] = None
+    attachment_data["description"] = "test"
+    attachment_data["attached_file"] = None
+
+    url = reverse('userstory-attachments-list')
+
+    client.login(us.owner)
+    response = client.post(url, attachment_data)
+    assert response.status_code == 400
+
+
+def test_create_attachment_on_wrong_project(client):
+    issue1 = f.create_issue()
+    issue2 = f.create_issue(owner=issue1.owner)
+
+    assert issue1.owner == issue2.owner
+    assert issue1.project.owner == issue2.project.owner
+
+    url = reverse("issue-attachments-list")
+
+    data = {"description": "test",
+            "object_id": issue2.pk,
+            "project": issue1.project.id,
+            "attached_file": SimpleUploadedFile("test.txt", b"test")}
+
+    client.login(issue1.owner)
+    response = client.post(url, data)
+    assert response.status_code == 400
diff --git a/tests/integration/test_issues.py b/tests/integration/test_issues.py
index f367d6df..cd9439c2 100644
--- a/tests/integration/test_issues.py
+++ b/tests/integration/test_issues.py
@@ -1,13 +1,13 @@
 from unittest import mock
 
-import pytest
-
 from django.core.urlresolvers import reverse
 
 from taiga.projects.issues import services, models
+from taiga.base.utils import json
 
 from .. import factories as f
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -51,7 +51,7 @@ def test_api_create_issues_in_bulk(client):
             "project_id": project.id}
 
     client.login(project.owner)
-    response = client.json.post(url, data)
+    response = client.json.post(url, json.dumps(data))
 
     assert response.status_code == 200, response.data
 
diff --git a/tests/integration/test_memberships.py b/tests/integration/test_memberships.py
index 400c8a6f..4387de9f 100644
--- a/tests/integration/test_memberships.py
+++ b/tests/integration/test_memberships.py
@@ -1,13 +1,12 @@
 from unittest import mock
-
-import pytest
-
 from django.core.urlresolvers import reverse
 
 from taiga.projects import services
+from taiga.base.utils import json
 
 from .. import factories as f
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -47,7 +46,7 @@ def test_api_create_bulk_members(client):
         ]
     }
     client.login(project.owner)
-    response = client.json.post(url, data)
+    response = client.json.post(url, json.dumps(data))
 
     assert response.status_code == 200
     assert response.data[0]["email"] == john.email
@@ -76,7 +75,7 @@ def test_api_invite_existing_user(client, outbox):
     url = reverse("memberships-list")
     data = {"role": role.pk, "project": role.project.pk, "email": user.email}
 
-    response = client.json.post(url, data)
+    response = client.json.post(url, json.dumps(data))
 
     assert response.status_code == 201, response.data
     assert len(outbox) == 1
diff --git a/tests/integration/test_projects.py b/tests/integration/test_projects.py
index a9996cc8..7d25ac32 100644
--- a/tests/integration/test_projects.py
+++ b/tests/integration/test_projects.py
@@ -1,9 +1,9 @@
-import pytest
-
 from django.core.urlresolvers import reverse
+from taiga.base.utils import json
 
 from .. import factories as f
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -13,7 +13,7 @@ def test_api_create_project(client):
     data = {"name": "project name", "description": "project description"}
 
     client.login(user)
-    response = client.json.post(url, data)
+    response = client.json.post(url, json.dumps(data))
 
     assert response.status_code == 201
 
@@ -24,6 +24,6 @@ def test_api_partially_update_project(client):
     data = {"name": ""}
 
     client.login(project.owner)
-    response = client.json.patch(url, data)
+    response = client.json.patch(url, json.dumps(data))
 
     assert response.status_code == 400
diff --git a/tests/integration/test_tasks.py b/tests/integration/test_tasks.py
index c6ed5d9b..46caa4b0 100644
--- a/tests/integration/test_tasks.py
+++ b/tests/integration/test_tasks.py
@@ -1,13 +1,13 @@
 from unittest import mock
 
-import pytest
-
 from django.core.urlresolvers import reverse
 
+from taiga.base.utils import json
 from taiga.projects.tasks import services
 
 from .. import factories as f
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -40,7 +40,7 @@ def test_api_update_task_tags(client):
     data = {"tags": ["back", "front"], "version": task.version}
 
     client.login(task.owner)
-    response = client.json.patch(url, data)
+    response = client.json.patch(url, json.dumps(data))
 
     assert response.status_code == 200, response.data
 
@@ -57,7 +57,7 @@ def test_api_create_in_bulk_with_status(client):
     }
 
     client.login(us.owner)
-    response = client.json.post(url, data)
+    response = client.json.post(url, json.dumps(data))
 
     assert response.status_code == 200
     assert response.data[0]["status"] == us.project.default_task_status.id
diff --git a/tests/integration/test_userstories.py b/tests/integration/test_userstories.py
index 8ae87dfb..ee17c198 100644
--- a/tests/integration/test_userstories.py
+++ b/tests/integration/test_userstories.py
@@ -1,13 +1,13 @@
 from unittest import mock
 
-import pytest
-
 from django.core.urlresolvers import reverse
 
+from taiga.base.utils import json
 from taiga.projects.userstories import services, models
 
 from .. import factories as f
 
+import pytest
 pytestmark = pytest.mark.django_db
 
 
@@ -76,7 +76,7 @@ def test_api_create_in_bulk_with_status(client):
     }
 
     client.login(project.owner)
-    response = client.json.post(url, data)
+    response = client.json.post(url, json.dumps(data))
 
     assert response.status_code == 200, response.data
     assert response.data[0]["status"] == project.default_us_status.id
@@ -94,6 +94,6 @@ def test_api_update_order_in_bulk(client):
     }
 
     client.login(project.owner)
-    response = client.json.post(url, data)
+    response = client.json.post(url, json.dumps(data))
 
     assert response.status_code == 204, response.data
diff --git a/tests/utils.py b/tests/utils.py
index 4537c911..f326505e 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -88,19 +88,21 @@ class SettingsTestCase(object):
         override_settings(cls.ORIGINAL_SETTINGS)
         cls.OVERRIDE_SETTINGS.clear()
 
-def _helper_test_http_method_responses(client, method, url, data, users, after_each_request=None):
+def _helper_test_http_method_responses(client, method, url, data, users, after_each_request=None,
+                                       content_type="application/json"):
     results = []
+
     for user in users:
         if user is None:
             client.logout()
         else:
             client.login(user)
         if data:
-            response = getattr(client, method)(url, data, content_type="application/json")
+            response = getattr(client, method)(url, data, content_type=content_type)
         else:
             response = getattr(client, method)(url)
-        if response.status_code == 400:
-            print(response.content)
+        if response.status_code >= 400:
+            print("Response content:", response.content)
 
         results.append(response)
 
@@ -108,8 +110,10 @@ def _helper_test_http_method_responses(client, method, url, data, users, after_e
             after_each_request()
     return results
 
-def helper_test_http_method(client, method, url, data, users, after_each_request=None):
-    responses = _helper_test_http_method_responses(client, method, url, data, users, after_each_request)
+def helper_test_http_method(client, method, url, data, users, after_each_request=None,
+                            content_type="application/json"):
+    responses = _helper_test_http_method_responses(client, method, url, data, users, after_each_request,
+                                                   content_type=content_type)
     return list(map(lambda r: r.status_code, responses))