diff --git a/marathon/models/container.py b/marathon/models/container.py
index 286730e..bb9520b 100644
--- a/marathon/models/container.py
+++ b/marathon/models/container.py
@@ -15,15 +15,18 @@ class MarathonContainer(MarathonObject):
     :type volumes: list[:class:`marathon.models.container.MarathonContainerVolume`] or list[dict]
     """
 
-    TYPES = ['DOCKER']
+    TYPES = ['DOCKER', 'MESOS']
     """Valid container types"""
 
     def __init__(self, docker=None, type='DOCKER', volumes=None):
         if type not in self.TYPES:
             raise InvalidChoiceError('type', type, self.TYPES)
         self.type = type
-        self.docker = docker if isinstance(docker, MarathonDockerContainer) \
-            else MarathonDockerContainer().from_json(docker)
+
+        if docker:
+            self.docker = docker if isinstance(docker, MarathonDockerContainer) \
+                else MarathonDockerContainer().from_json(docker)
+
         self.volumes = [
             v if isinstance(
                 v, MarathonContainerVolume) else MarathonContainerVolume().from_json(v)