diff --git a/federationapi/internal/perform.go b/federationapi/internal/perform.go
index 4220c6a56..603e2a9c9 100644
--- a/federationapi/internal/perform.go
+++ b/federationapi/internal/perform.go
@@ -562,7 +562,7 @@ func (r *FederationInternalAPI) PerformLeave(
 		// Build the leave event.
 		event, err := respMakeLeave.LeaveEvent.Build(
 			time.Now(),
-			r.cfg.Matrix.ServerName,
+			origin,
 			r.cfg.Matrix.KeyID,
 			r.cfg.Matrix.PrivateKey,
 			respMakeLeave.RoomVersion,