diff --git a/smash/web/migrations/0036_year_of_diagnosis_default.py b/smash/web/migrations/0036_year_of_diagnosis_default.py
new file mode 100644
index 0000000000000000000000000000000000000000..173f64b200ff28e468d0e26b6b1ce5ebf5271e8a
--- /dev/null
+++ b/smash/web/migrations/0036_year_of_diagnosis_default.py
@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.3 on 2017-04-25 07:28
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('web', '0035_screening_number'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='subject',
+            name='year_of_diagnosis',
+            field=models.IntegerField(blank=True, null=True, verbose_name=b'Year of diagnosis (YYYY)'),
+        ),
+        migrations.RunSQL(
+            "UPDATE web_subject SET year_of_diagnosis=NULL WHERE year_of_diagnosis = 0;",
+            "UPDATE web_subject SET year_of_diagnosis=0 WHERE year_of_diagnosis = NULL;"),
+    ]
diff --git a/smash/web/models/subject.py b/smash/web/models/subject.py
index 394c7df1e7dd16abd80e67316c7ff4715a68fd55..d6543711467db469a5cbdb82f115fb4d8e6dec03 100644
--- a/smash/web/models/subject.py
+++ b/smash/web/models/subject.py
@@ -138,7 +138,6 @@ class Subject(models.Model):
                                  verbose_name='Diagnosis'
                                  )
     year_of_diagnosis = models.IntegerField(
-        default=0,
         null=True,
         blank=True,
         verbose_name='Year of diagnosis (YYYY)'
diff --git a/smash/web/tests/test_SubjectAddForm.py b/smash/web/tests/test_SubjectAddForm.py
index 5e20ce73466e21b344a66516f2def31c8e06c696..bfdab7a83f04f92cae6ac0519e126016abfb0f2c 100644
--- a/smash/web/tests/test_SubjectAddForm.py
+++ b/smash/web/tests/test_SubjectAddForm.py
@@ -39,6 +39,7 @@ class SubjectAddFormTests(TestCase):
         form = SubjectAddForm(data=form_data, user=self.user)
         form.is_valid()
         self.assertTrue(form.is_valid())
+        self.assertIsNone(form.fields['year_of_diagnosis'].initial)
         form.save()
 
         form2 = SubjectAddForm(data=form_data, user=self.user)