From 304c83d11853163c3dbb82f5f9015234c340d023 Mon Sep 17 00:00:00 2001
From: Timo Tuominen <tituomin@gmail.com>
Date: Mon, 22 Jan 2018 15:16:38 +0200
Subject: [PATCH] Fix cascading delete error

https://github.com/django-polymorphic/django-polymorphic/issues/229
---
 observations/models.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/observations/models.py b/observations/models.py
index b7c4af295..e521a9424 100644
--- a/observations/models.py
+++ b/observations/models.py
@@ -75,6 +75,7 @@ class Observation(PolymorphicModel):
         ObservableProperty,
         blank=False, null=False,
         help_text='The property observed')
+    _base_manager = models.Manager()
     class Meta:
         ordering = ['-time']