diff --git a/federationsender/internal/perform.go b/federationsender/internal/perform.go
index 831622efe..96b1149d9 100644
--- a/federationsender/internal/perform.go
+++ b/federationsender/internal/perform.go
@@ -97,7 +97,7 @@ func (r *FederationSenderInternalAPI) PerformJoin(
 	} else {
 		response.LastError = &gomatrix.HTTPError{
 			Code:         0,
-			WrappedError: lastErr,
+			WrappedError: nil,
 			Message:      lastErr.Error(),
 		}
 	}
diff --git a/sytest-whitelist b/sytest-whitelist
index ea175e7ce..eb28898ab 100644
--- a/sytest-whitelist
+++ b/sytest-whitelist
@@ -371,3 +371,5 @@ Inbound federation rejects attempts to join v2 rooms from servers lacking versio
 Inbound federation rejects attempts to join v2 rooms from servers only supporting v1
 Outbound federation passes make_join failures through to the client
 Outbound federation correctly handles unsupported room versions
+Remote users may not join unfederated rooms
+Guest users denied access over federation if guest access prohibited