diff --git a/watson/migrations/0001_initial.py b/watson/migrations/0001_initial.py
index 6b7af3b..8eab3dc 100644
--- a/watson/migrations/0001_initial.py
+++ b/watson/migrations/0001_initial.py
@@ -32,7 +32,7 @@ class Migration(migrations.Migration):
                 ('content', models.TextField(blank=True)),
                 ('url', models.CharField(max_length=1000, blank=True)),
                 ('meta_encoded', models.TextField()),
-                ('content_type', models.ForeignKey(to='contenttypes.ContentType')),
+                ('content_type', models.ForeignKey(to='contenttypes.ContentType', on_delete=models.CASCADE)),
             ],
             options={
                 'verbose_name_plural': 'search entries',
diff --git a/watson/models.py b/watson/models.py
index fb3d382..c3cf44f 100644
--- a/watson/models.py
+++ b/watson/models.py
@@ -40,6 +40,7 @@ class SearchEntry(models.Model):
 
     content_type = models.ForeignKey(
         ContentType,
+        on_delete = models.CASCADE,
     )
 
     object_id = models.TextField()