1 files changed, 5 insertions, 1 deletions
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index 8b9766fab7..21ededc5ae 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -27,6 +27,7 @@ class Codes(object):
     BAD_PAGINATION = "M_BAD_PAGINATION"
     UNKNOWN = "M_UNKNOWN"
     NOT_FOUND = "M_NOT_FOUND"
+    UNKNOWN_TOKEN = "M_UNKNOWN_TOKEN"
 
 
 class CodeMessageException(Exception):
@@ -74,7 +75,10 @@ class AuthError(SynapseError):
 
 class EventStreamError(SynapseError):
     """An error raised when there a problem with the event stream."""
-    pass
+    def __init__(self, *args, **kwargs):
+        if "errcode" not in kwargs:
+            kwargs["errcode"] = Codes.BAD_PAGINATION
+        super(EventStreamError, self).__init__(*args, **kwargs)
 
 
 class LoginError(SynapseError):