diff --git a/longs/migrations/0029_auto_20210225_1819.py b/longs/migrations/0029_auto_20210225_1819.py
new file mode 100644
index 00000000..2a12790e
--- /dev/null
+++ b/longs/migrations/0029_auto_20210225_1819.py
@@ -0,0 +1,25 @@
+# Generated by Django 3.1.3 on 2021-02-25 18:19
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('generic', '0009_contrast'),
+        ('longs', '0028_longseries_contrast'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='longseries',
+            name='contrast',
+            field=models.ForeignKey(blank=True, help_text='MRI / CT contrast', null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='series_contrast', to='generic.contrast'),
+        ),
+        migrations.AlterField(
+            model_name='longseries',
+            name='plane',
+            field=models.ForeignKey(blank=True, help_text='Plane of the examination', null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='series_plane', to='generic.plane'),
+        ),
+    ]
diff --git a/longs/models.py b/longs/models.py
index 0f201765..c6796a07 100644
--- a/longs/models.py
+++ b/longs/models.py
@@ -193,6 +193,7 @@ class LongSeries(models.Model):
         related_name="series_plane",
         on_delete=models.SET_NULL,
         null=True,
+        blank=True,
     )
     contrast = models.ForeignKey(
         Contrast,
@@ -200,6 +201,7 @@ class LongSeries(models.Model):
         related_name="series_contrast",
         on_delete=models.SET_NULL,
         null=True,
+        blank=True,
     )
     long = models.ManyToManyField(
         "Long",