--- a/svghmi/svghmi_server.py	Fri Jan 17 16:25:45 2020 +0100
+++ b/svghmi/svghmi_server.py	Tue Jan 21 13:55:03 2020 +0100
@@ -193,3 +193,11 @@
     svghmi_send_thread.join()
     svghmi_send_thread = None
 
+
+class NoCacheFile(File):
+    def render_GET(self, request):
+        request.setHeader(b"Cache-Control", b"no-cache, no-store")
+        return File.render_GET(self, request)
+    render_HEAD = render_GET
+
+