diff --git a/synapse/rest/client/v1/pusher.py b/synapse/rest/client/v1/pusher.py
index b84f0260f2c898e1a64ca6d80b358d18e71716ed..4c07ae7f45b44de9084cc2ab6688da5b92dee77c 100644
--- a/synapse/rest/client/v1/pusher.py
+++ b/synapse/rest/client/v1/pusher.py
@@ -142,7 +142,7 @@ class PushersRemoveRestServlet(RestServlet):
To allow pusher to be delete by clicking a link (ie. GET request)
"""
PATTERNS = client_path_patterns("/pushers/remove$")
- SUCCESS_HTML = "<html><body>You have been unsubscribed</body><html>"
+ SUCCESS_HTML = b"<html><body>You have been unsubscribed</body><html>"
def __init__(self, hs):
super(PushersRemoveRestServlet, self).__init__()