diff --git a/georiviere/knowledge/admin.py b/georiviere/knowledge/admin.py
index 4c448019..d6e60620 100644
--- a/georiviere/knowledge/admin.py
+++ b/georiviere/knowledge/admin.py
@@ -1,23 +1,21 @@
 from django.contrib import admin
 
 from georiviere.knowledge.models import (
-    Vegetation, VegetationState, VegetationStrata, VegetationType,
+    VegetationState, VegetationStrata, VegetationType,
     VegetationAgeClassDiversity, VegetationThicknessType, VegetationSpecificDiversity,
-    Work, WorkBankEffect, WorkFishContinuityEffect, WorkSedimentEffect,
+    WorkBankEffect, WorkFishContinuityEffect, WorkSedimentEffect,
     WorkWaterEffect, WorkBedEffect,
     WorkStreamInfluence, WorkMaterial, WorkState, WorkType, KnowledgeType,
     FollowUpType
 )
 
 admin.site.register(KnowledgeType, admin.ModelAdmin)
-admin.site.register(Vegetation)
 admin.site.register(VegetationAgeClassDiversity, admin.ModelAdmin)
 admin.site.register(VegetationSpecificDiversity, admin.ModelAdmin)
 admin.site.register(VegetationState, admin.ModelAdmin)
 admin.site.register(VegetationStrata, admin.ModelAdmin)
 admin.site.register(VegetationThicknessType, admin.ModelAdmin)
 admin.site.register(VegetationType, admin.ModelAdmin)
-admin.site.register(Work)
 admin.site.register(WorkBankEffect, admin.ModelAdmin)
 admin.site.register(WorkStreamInfluence, admin.ModelAdmin)
 admin.site.register(WorkFishContinuityEffect, admin.ModelAdmin)
diff --git a/georiviere/knowledge/tests/test_forms.py b/georiviere/knowledge/tests/test_forms.py
new file mode 100644
index 00000000..1305b770
--- /dev/null
+++ b/georiviere/knowledge/tests/test_forms.py
@@ -0,0 +1,31 @@
+from django.test import TestCase
+
+from geotrek.authent.tests.factories import StructureFactory
+
+from georiviere.tests.factories import UserAllPermsFactory
+from georiviere.knowledge.forms import KnowledgeForm
+from . import factories
+
+
+class KnowledgeFormTest(TestCase):
+    """Test knowledge forms"""
+
+    @classmethod
+    def setUpTestData(cls):
+        cls.user = UserAllPermsFactory(password='booh')
+        cls.knowledge = factories.KnowledgeFactory()
+
+    def test_update_knowledge(self):
+        """Test create new knowledge"""
+        data = {
+            'structure': self.knowledge.structure,
+            'name': 'New name',
+            'description': self.knowledge.description,
+            'geom': self.knowledge.geom.ewkt,
+        }
+        knowledge_form_update = KnowledgeForm(
+            user=self.user,
+            instance=self.knowledge,
+            data=data
+        )
+        self.assertTrue(knowledge_form_update.is_valid())
diff --git a/georiviere/river/fields.py b/georiviere/river/fields.py
index f8014ed0..d57e98f5 100644
--- a/georiviere/river/fields.py
+++ b/georiviere/river/fields.py
@@ -15,12 +15,18 @@
 logger = logging.getLogger(__name__)
 
 
-class SnappedFieldMixin(object):
+class SnappedFieldMixin:
     """
     It's a Geometry field, with additional information about snapped vertices.
     """
     widget = SnappedGeometryWidget
 
+
+class ForceSnapFieldMixin(SnappedFieldMixin):
+    """
+    It's a Geometry field, with additional information about snapped vertices, and force snap on validation
+    """
+
     default_error_messages = {
         'invalid_snap_line': _('Geometry invalid snapping.'),
     }