diff --git a/cmd/syncthing/gui.go b/cmd/syncthing/gui.go
index ed43ce098..b92f1706b 100644
--- a/cmd/syncthing/gui.go
+++ b/cmd/syncthing/gui.go
@@ -145,6 +145,9 @@ func startGUI(cfg config.GUIConfiguration, assetDir string, m *model.Model) erro
 	// protected, other requests will grant cookies.
 	handler := csrfMiddleware("/rest", mux)
 
+	// Add our version as a header to responses
+	handler = withVersionMiddleware(handler)
+
 	// Wrap everything in basic auth, if user/password is set.
 	if len(cfg.User) > 0 {
 		handler = basicAuthMiddleware(cfg.User, cfg.Password, handler)
@@ -174,6 +177,13 @@ func noCacheMiddleware(h http.Handler) http.Handler {
 	})
 }
 
+func withVersionMiddleware(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("X-Syncthing-Version", Version)
+		h.ServeHTTP(w, r)
+	})
+}
+
 func withModel(m *model.Model, h func(m *model.Model, w http.ResponseWriter, r *http.Request)) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		h(m, w, r)