diff --git a/nix/README.md b/nix/README.md
index bd6f0962f3ebbda806b457aae76d7134835e96d5..6062165bb384e0224fe87e8a2836e9c14b820a05 100644
--- a/nix/README.md
+++ b/nix/README.md
@@ -69,6 +69,9 @@ let
     {
       "m.homeserver": {
         "base_url": "https://${matrix_hostname}"
+      },
+      "org.matrix.msc3575.proxy": {
+        "url": "https://${matrix_hostname}"
       }
     }
   '';