diff --git a/commentaries/migrations/0015_auto_20170726_1615.py b/commentaries/migrations/0015_auto_20170726_1615.py
new file mode 100644
index 0000000000000000000000000000000000000000..34a805eeb7f6c3e07632f800f8214f7a3cb2a764
--- /dev/null
+++ b/commentaries/migrations/0015_auto_20170726_1615.py
@@ -0,0 +1,60 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.3 on 2017-07-26 14:15
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+def do_nothing(apps, schema_editor):
+    return
+
+
+def fill_empty_strings_for_nulls(apps, schema_editor):
+    Commentary = apps.get_model('commentaries', 'Commentary')
+    Commentary.objects.filter(arxiv_identifier__isnull=True).update(arxiv_identifier='')
+    Commentary.objects.filter(arxiv_or_DOI_string__isnull=True).update(arxiv_or_DOI_string='')
+    Commentary.objects.filter(journal__isnull=True).update(journal='')
+    Commentary.objects.filter(pages__isnull=True).update(pages='')
+    Commentary.objects.filter(pub_DOI__isnull=True).update(pub_DOI='')
+    Commentary.objects.filter(volume__isnull=True).update(volume='')
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('commentaries', '0014_auto_20170201_1243'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='commentary',
+            name='arxiv_identifier',
+            field=models.CharField(blank=True, default='', max_length=100, null=True, verbose_name='arXiv identifier (including version nr)'),
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='arxiv_or_DOI_string',
+            field=models.CharField(default='', max_length=100, null=True, verbose_name='string form of arxiv nr or DOI for commentary url'),
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='journal',
+            field=models.CharField(blank=True, default='', max_length=300, null=True),
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='pages',
+            field=models.CharField(blank=True, default='', max_length=50, null=True),
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='pub_DOI',
+            field=models.CharField(blank=True, default='', max_length=200, null=True, verbose_name='DOI of the original publication'),
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='volume',
+            field=models.CharField(blank=True, default='', max_length=50, null=True),
+        ),
+        migrations.RunPython(fill_empty_strings_for_nulls, do_nothing),
+    ]
diff --git a/commentaries/migrations/0016_auto_20170726_1616.py b/commentaries/migrations/0016_auto_20170726_1616.py
new file mode 100644
index 0000000000000000000000000000000000000000..63e1a1ea5a56f469c28a29d391c19122e76cb056
--- /dev/null
+++ b/commentaries/migrations/0016_auto_20170726_1616.py
@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.3 on 2017-07-26 14:16
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('commentaries', '0015_auto_20170726_1615'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='commentary',
+            name='arxiv_identifier',
+            field=models.CharField(blank=True, default='', max_length=100, verbose_name='arXiv identifier (including version nr)'),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='arxiv_or_DOI_string',
+            field=models.CharField(default='', max_length=100, verbose_name='string form of arxiv nr or DOI for commentary url'),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='journal',
+            field=models.CharField(blank=True, default='', max_length=300),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='pages',
+            field=models.CharField(blank=True, default='', max_length=50),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='pub_DOI',
+            field=models.CharField(blank=True, default='', max_length=200, verbose_name='DOI of the original publication'),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='commentary',
+            name='volume',
+            field=models.CharField(blank=True, default='', max_length=50),
+            preserve_default=False,
+        ),
+    ]
diff --git a/scipost/migrations/0060_auto_20170726_1612.py b/scipost/migrations/0060_auto_20170726_1612.py
new file mode 100644
index 0000000000000000000000000000000000000000..5faee7244032b1e0960daea7615c4adc1512b9d0
--- /dev/null
+++ b/scipost/migrations/0060_auto_20170726_1612.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.3 on 2017-07-26 14:12
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('scipost', '0059_auto_20170701_1356'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='contributor',
+            name='address',
+            field=models.CharField(blank=True, max_length=1000, verbose_name='address'),
+        ),
+    ]