diff --git a/server.go b/server.go
index 637960d..24a50cd 100644
--- a/server.go
+++ b/server.go
@@ -69,7 +69,7 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 func (h *Handler) handleOptions(w http.ResponseWriter, r *http.Request) error {
 	w.Header().Add("Allow", "OPTIONS, GET, HEAD, PROPFIND")
-	w.Header().Add("DAV", "1")
+	w.Header().Add("DAV", "1, 3")
 	w.WriteHeader(http.StatusNoContent)
 	return nil
 }