diff --git a/requirements.txt b/requirements.txt
index 391151c..c85898b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
-django-mptt==0.9.1
+django-mptt==0.14.0
 factory-boy==2.11.1
 mock==2.0.0
 pyhamcrest==1.9.0
-django-cte==1.1.4
+django-cte==1.2.1
 django-codemirror2==0.2
 behave-django==1.3.0
\ No newline at end of file
diff --git a/river/models/base_model.py b/river/models/base_model.py
index c34f46b..f3b10c3 100644
--- a/river/models/base_model.py
+++ b/river/models/base_model.py
@@ -1,7 +1,10 @@
 from django.conf import settings
 
 from django.db import models
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models.managers.rivermanager import RiverManager
 
diff --git a/river/models/function.py b/river/models/function.py
index 490e84e..0c3e3da 100644
--- a/river/models/function.py
+++ b/river/models/function.py
@@ -3,7 +3,10 @@
 
 from django.db import models
 from django.db.models.signals import pre_save
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models import BaseModel
 
diff --git a/river/models/hook.py b/river/models/hook.py
index e4d3984..e03da60 100644
--- a/river/models/hook.py
+++ b/river/models/hook.py
@@ -3,7 +3,10 @@
 from django.contrib.contenttypes.models import ContentType
 from django.db import models
 from django.db.models import PROTECT
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models import Workflow, GenericForeignKey, BaseModel
 from river.models.function import Function
diff --git a/river/models/on_approved_hook.py b/river/models/on_approved_hook.py
index cf15d68..967da39 100644
--- a/river/models/on_approved_hook.py
+++ b/river/models/on_approved_hook.py
@@ -1,6 +1,9 @@
 from django.db import models
 from django.db.models import CASCADE
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models import TransitionApprovalMeta, TransitionApproval
 from river.models.hook import Hook
diff --git a/river/models/on_transit_hook.py b/river/models/on_transit_hook.py
index e6c019e..2114bb3 100644
--- a/river/models/on_transit_hook.py
+++ b/river/models/on_transit_hook.py
@@ -1,6 +1,9 @@
 from django.db import models
 from django.db.models import CASCADE
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models import TransitionMeta, Transition
 from river.models.hook import Hook
diff --git a/river/models/state.py b/river/models/state.py
index 12ade30..a606ea0 100644
--- a/river/models/state.py
+++ b/river/models/state.py
@@ -9,7 +9,10 @@
 except ImportError:
     from six import python_2_unicode_compatible
 
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models.base_model import BaseModel
 from river.models.managers.state import StateManager
diff --git a/river/models/transition.py b/river/models/transition.py
index b295273..5d411a7 100644
--- a/river/models/transition.py
+++ b/river/models/transition.py
@@ -10,7 +10,10 @@
     from django.contrib.contenttypes.generic import GenericForeignKey
 
 from django.db import models
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models.base_model import BaseModel
 from river.models.managers.transitionapproval import TransitionApprovalManager
diff --git a/river/models/transitionapproval.py b/river/models/transitionapproval.py
index 92964d3..da789ce 100644
--- a/river/models/transitionapproval.py
+++ b/river/models/transitionapproval.py
@@ -12,7 +12,10 @@
     from django.contrib.contenttypes.generic import GenericForeignKey
 
 from django.db import models
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models.base_model import BaseModel
 from river.models.managers.transitionapproval import TransitionApprovalManager
diff --git a/river/models/transitionapprovalmeta.py b/river/models/transitionapprovalmeta.py
index b1c2f74..f965cf0 100644
--- a/river/models/transitionapprovalmeta.py
+++ b/river/models/transitionapprovalmeta.py
@@ -3,8 +3,10 @@
 from django.db import models, transaction
 from django.db.models import PROTECT
 from django.db.models.signals import post_save, pre_delete
-from django.utils.translation import ugettext_lazy as _
-
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 from river.config import app_config
 from river.models import Workflow
 from river.models.base_model import BaseModel
diff --git a/river/models/transitionmeta.py b/river/models/transitionmeta.py
index 224bdf9..c48da90 100644
--- a/river/models/transitionmeta.py
+++ b/river/models/transitionmeta.py
@@ -2,7 +2,10 @@
 
 from django.db import models
 from django.db.models import PROTECT
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.models import State, Workflow
 from river.models.base_model import BaseModel
diff --git a/river/models/workflow.py b/river/models/workflow.py
index aee0901..336ac62 100644
--- a/river/models/workflow.py
+++ b/river/models/workflow.py
@@ -1,6 +1,9 @@
 from django.db import models
 from django.db.models import PROTECT
-from django.utils.translation import ugettext_lazy as _
+try:
+    from django.utils.translation import ugettext_lazy as _
+except ImportError:
+    from django.utils.translation import gettext_lazy as _
 
 from river.config import app_config
 from river.models import BaseModel, State
diff --git a/river/signals.py b/river/signals.py
index bc1ff44..9dbcf30 100644
--- a/river/signals.py
+++ b/river/signals.py
@@ -10,14 +10,14 @@
 from river.models.on_complete_hook import OnCompleteHook
 from river.models.on_transit_hook import OnTransitHook
 
-pre_on_complete = Signal(providing_args=["workflow_object", "field_name", ])
-post_on_complete = Signal(providing_args=["workflow_object", "field_name", ])
+pre_on_complete = Signal()
+post_on_complete = Signal()
 
-pre_transition = Signal(providing_args=["workflow_object", "field_name", "source_state", "destination_state"])
-post_transition = Signal(providing_args=["workflow_object", "field_name", "source_state", "destination_state"])
+pre_transition = Signal()
+post_transition = Signal()
 
-pre_approve = Signal(providing_args=["workflow_object", "field_name", "transition_approval"])
-post_approve = Signal(providing_args=["workflow_object", "field_name", "transition_approval", "transition_approval_meta"])
+pre_approve = Signal()
+post_approve = Signal()
 
 LOGGER = logging.getLogger(__name__)