diff --git a/roomserver/api/perform.go b/roomserver/api/perform.go
index 0b8e6df2..12ba1516 100644
--- a/roomserver/api/perform.go
+++ b/roomserver/api/perform.go
@@ -38,6 +38,11 @@ func (p *PerformError) JSONResponse() util.JSONResponse {
 			Code: http.StatusForbidden,
 			JSON: jsonerror.Forbidden(p.Msg),
 		}
+	case PerformErrorNoOperation:
+		return util.JSONResponse{
+			Code: http.StatusForbidden,
+			JSON: jsonerror.Forbidden(p.Msg),
+		}
 	default:
 		return util.ErrorResponse(p)
 	}
diff --git a/sytest-blacklist b/sytest-blacklist
index 9f140ed1..65e6c1b1 100644
--- a/sytest-blacklist
+++ b/sytest-blacklist
@@ -45,6 +45,9 @@ Can recv device messages over federation
 Device messages over federation wake up /sync
 Wildcard device messages over federation wake up /sync
 
+# See https://github.com/matrix-org/sytest/pull/901
+Remote invited user can see room metadata
+
 # We don't implement soft-failed events yet, but because the /send response is vague,
 # this test thinks it's all fine...
 Inbound federation accepts a second soft-failed event
diff --git a/sytest-whitelist b/sytest-whitelist
index 0036d60e..18bb7ca4 100644
--- a/sytest-whitelist
+++ b/sytest-whitelist
@@ -357,6 +357,8 @@ Getting state checks the events requested belong to the room
 Getting state IDs checks the events requested belong to the room
 Can invite users to invite-only rooms
 Uninvited users cannot join the room
+Users cannot invite themselves to a room
+Users cannot invite a user that is already in the room
 Invited user can reject invite
 Invited user can reject invite for empty room
 Invited user can reject local invite after originator leaves