diff --git a/octodns/provider/mythicbeasts.py b/octodns/provider/mythicbeasts.py
index af07ddb..8bd2979 100644
--- a/octodns/provider/mythicbeasts.py
+++ b/octodns/provider/mythicbeasts.py
@@ -13,6 +13,8 @@ from logging import getLogger
 from ..record import Record
 from .base import BaseProvider
 
+from collections import defaultdict
+
 
 def add_trailing_dot(value):
     '''
@@ -43,6 +45,19 @@ class MythicBeastsUnauthorizedException(Exception):
             self.message, self.zone, *args)
 
 
+class MythicBeastsRecordException(Exception):
+    def __init__(self, zone, command, *args):
+        self.zone = zone
+        self.command = command
+        self.message = 'Mythic Beasts could not action command: {} {}'.format(
+            self.zone,
+            self.command,
+        )
+
+        super(MythicBeastsRecordException, self).__init__(
+            self.message, self.zone, self.command, *args)
+
+
 class MythicBeastsProvider(BaseProvider):
     '''
     Mythic Beasts DNS API Provider
@@ -118,6 +133,12 @@ class MythicBeastsProvider(BaseProvider):
 
         if resp.status_code == 401:
             raise MythicBeastsUnauthorizedException(data['domain'])
+
+        if resp.status_code == 400:
+            raise MythicBeastsRecordException(
+                data['domain'],
+                data['command']
+            )
         resp.raise_for_status()
         return resp
 
@@ -287,7 +308,11 @@ class MythicBeastsProvider(BaseProvider):
 
         before = len(zone.records)
         exists = False
-        data = dict()
+        data = defaultdict(lambda: defaultdict(lambda: {
+            'raw_values': [],
+            'name': None,
+            'zone': None,
+        }))
 
         exists = True
         for line in resp.content.splitlines():
@@ -310,10 +335,6 @@ class MythicBeastsProvider(BaseProvider):
                 _value = _value.replace(';', '\\;')
 
             if hasattr(self, '_data_for_{}'.format(_type)):
-
-                if _type not in data:
-                    data[_type] = dict()
-
                 if _name not in data[_type]:
                     data[_type][_name] = {
                         'raw_values': [{'value': _value, 'ttl': _ttl}],
diff --git a/tests/test_octodns_provider_mythicbeasts.py b/tests/test_octodns_provider_mythicbeasts.py
index 5deba3b..2a3b85b 100644
--- a/tests/test_octodns_provider_mythicbeasts.py
+++ b/tests/test_octodns_provider_mythicbeasts.py
@@ -318,6 +318,27 @@ class TestMythicBeastsProvider(TestCase):
 
         self.assertEquals(0, len(zone.records))
 
+        # Record change failed
+        with requests_mock() as mock:
+            mock.post(ANY, status_code=200, text='')
+            provider.populate(zone)
+            zone.add_record(Record.new(zone, 'prawf', {
+                'ttl': 300,
+                'type': 'TXT',
+                'value': 'prawf',
+            }))
+            plan = provider.plan(zone)
+
+        with requests_mock() as mock:
+            mock.post(ANY, status_code=400, text='NADD 300 TXT prawf')
+
+            with self.assertRaises(Exception) as err:
+                provider.apply(plan)
+            self.assertEquals(
+                'Mythic Beasts could not action command: unit.tests '
+                'ADD prawf.unit.tests 300 TXT prawf',
+                err.exception.message)
+
         # Check deleting and adding/changing test record
         existing = 'prawf 300 TXT prawf prawf prawf\ndileu 300 TXT dileu'