diff --git a/docs/changelog.rst b/docs/changelog.rst
index 409fb347c..a63eae574 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -18,6 +18,15 @@ Please make sure you have a fresh **database backup** before upgrading! Upgradin
 
 
 
+v1.23.1 - 2018-08-26
+^^^^^^^^^^^^^^^^^^^^
+
+**Tickets resolved in this release:**
+
+- [`#515 <https://github.com/dennissiemensma/dsmr-reader/issues/515>`_] Missing mqtt values
+
+
+
 v1.23.0 - 2018-08-02
 ^^^^^^^^^^^^^^^^^^^^
 
diff --git a/dsmr_mqtt/migrations/0008_mqtt_null_payload.py b/dsmr_mqtt/migrations/0008_mqtt_null_payload.py
new file mode 100644
index 000000000..a79ef4632
--- /dev/null
+++ b/dsmr_mqtt/migrations/0008_mqtt_null_payload.py
@@ -0,0 +1,18 @@
+# Generated by Django 2.1 on 2018-08-26 12:30
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dsmr_mqtt', '0007_mqtts'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='message',
+            name='payload',
+            field=models.TextField(blank=True, null=True),
+        ),
+    ]
diff --git a/dsmr_mqtt/models/queue.py b/dsmr_mqtt/models/queue.py
index 4c7583f7e..c098ebb27 100644
--- a/dsmr_mqtt/models/queue.py
+++ b/dsmr_mqtt/models/queue.py
@@ -5,7 +5,7 @@
 class Message(models.Model):
     """ Queued message for MQTT. """
     topic = models.CharField(max_length=255)
-    payload = models.TextField()
+    payload = models.TextField(null=True, blank=True)
 
     def __str__(self):
         return self.topic
diff --git a/dsmr_mqtt/tests/models/test_queue.py b/dsmr_mqtt/tests/models/test_queue.py
index 92e13de39..e318019d9 100644
--- a/dsmr_mqtt/tests/models/test_queue.py
+++ b/dsmr_mqtt/tests/models/test_queue.py
@@ -15,3 +15,7 @@ def test_admin(self):
 
     def test_to_string(self):
         self.assertEqual(str(self.instance), '{}'.format(self.instance.topic))
+
+    def test_null_payload(self):
+        """ This caused many headaches in issue #515. """
+        Message.objects.create(topic='x', payload=None)
diff --git a/dsmrreader/__init__.py b/dsmrreader/__init__.py
index 75940247f..fb89722d1 100644
--- a/dsmrreader/__init__.py
+++ b/dsmrreader/__init__.py
@@ -17,6 +17,6 @@
 from django.utils.version import get_version
 
 
-VERSION = (1, 23, 0, 'final', 0)
+VERSION = (1, 23, 1, 'final', 0)
 
 __version__ = get_version(VERSION)