3 files changed, 17 insertions, 2 deletions
diff --git a/synapse/api/events/__init__.py b/synapse/api/events/__init__.py
index f95468fc65..5f300de108 100644
--- a/synapse/api/events/__init__.py
+++ b/synapse/api/events/__init__.py
@@ -157,7 +157,12 @@ class SynapseEvent(JsonEncodedObject):
 
 
 class SynapseStateEvent(SynapseEvent):
-     def __init__(self, **kwargs):
+
+    valid_keys = SynapseEvent.valid_keys + [
+        "prev_content",
+    ]
+
+    def __init__(self, **kwargs):
         if "state_key" not in kwargs:
             kwargs["state_key"] = ""
         super(SynapseStateEvent, self).__init__(**kwargs)
diff --git a/synapse/api/events/factory.py b/synapse/api/events/factory.py
index a3b293e024..5e38cdbc44 100644
--- a/synapse/api/events/factory.py
+++ b/synapse/api/events/factory.py
@@ -47,11 +47,14 @@ class EventFactory(object):
             self._event_list[event_class.TYPE] = event_class
 
         self.clock = hs.get_clock()
+        self.hs = hs
 
     def create_event(self, etype=None, **kwargs):
         kwargs["type"] = etype
         if "event_id" not in kwargs:
-            kwargs["event_id"] = random_string(10)
+            kwargs["event_id"] = "%s@%s" % (
+                random_string(10), self.hs.hostname
+            )
 
         if "ts" not in kwargs:
             kwargs["ts"] = int(self.clock.time_msec())
diff --git a/synapse/api/events/room.py b/synapse/api/events/room.py
index 33f0f0cb99..3a4dbc58ce 100644
--- a/synapse/api/events/room.py
+++ b/synapse/api/events/room.py
@@ -173,3 +173,10 @@ class RoomOpsPowerLevelsEvent(SynapseStateEvent):
 
     def get_content_template(self):
         return {}
+
+
+class RoomAliasesEvent(SynapseStateEvent):
+    TYPE = "m.room.aliases"
+
+    def get_content_template(self):
+        return {}