diff --git a/synapse/http/client.py b/synapse/http/client.py
index acc39742de..093bdf0e3f 100644
--- a/synapse/http/client.py
+++ b/synapse/http/client.py
@@ -180,7 +180,7 @@ class TwistedHttpClient(HttpClient):
         # TODO: setup and pass in an ssl_context to enable TLS
         endpoint = matrix_endpoint(
             reactor, destination, timeout=10,
-            ssl_context_factory=self.hs.tls_tls_context_factory
+            ssl_context_factory=self.hs.tls_context_factory
         )
 
         while True:
diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py
index d91500b07d..a6ebe23567 100644
--- a/synapse/http/endpoint.py
+++ b/synapse/http/endpoint.py
@@ -53,7 +53,7 @@ def matrix_endpoint(reactor, destination, ssl_context_factory=None,
         default_port = 8080
     else:
         transport_endpoint = SSL4ClientEndpoint
-        endpoint_kw_args.update(ssl_context_factory=ssl_context_factory)
+        endpoint_kw_args.update(sslContextFactory=ssl_context_factory)
         default_port = 443
 
     if port is None: