diff --git a/django_enumfield/db/fields.py b/django_enumfield/db/fields.py
index 37223ad..48e99e9 100644
--- a/django_enumfield/db/fields.py
+++ b/django_enumfield/db/fields.py
@@ -126,10 +126,9 @@ def set_enum(self, new_value):
                             "for enum {enum}."
                         ).format(value=new_value, enum=enum)
                     )
+            validators.validate_valid_transition(enum, old_value, new_value)
             setattr(self, private_att_name, new_value)
             self.__dict__[att_name] = new_value
-            # Run validation for new value.
-            validators.validate_valid_transition(enum, old_value, new_value)
 
         def get_enum(self):
             return getattr(self, private_att_name)
diff --git a/django_enumfield/tests/test_enum.py b/django_enumfield/tests/test_enum.py
index 35d4dbf..9263f0e 100644
--- a/django_enumfield/tests/test_enum.py
+++ b/django_enumfield/tests/test_enum.py
@@ -125,6 +125,12 @@ def test_enum_field_save(self):
         self.assertEqual(beer.state, BeerState.FIZZY)
         beer.save()
 
+    def test_invalid_transition_preserves_previous_value(self):
+        person = Person.objects.create(status=PersonStatus.ALIVE)
+        with self.assertRaises(InvalidStatusOperationError):
+            person.status = PersonStatus.UNBORN
+        self.assertEqual(person.status, PersonStatus.ALIVE)
+
     def test_enum_field_refresh_from_db(self):
         lamp = Lamp.objects.create(state=LampState.OFF)
         lamp2 = Lamp.objects.get(pk=lamp.id)