diff --git a/yunodiagnoser.py b/yunodiagnoser.py
index f9822d8..e883fcb 100644
--- a/yunodiagnoser.py
+++ b/yunodiagnoser.py
@@ -7,7 +7,7 @@ import socket
 
 from sanic import Sanic
 from sanic.log import logger
-from sanic.response import html, json as json_response
+from sanic.response import html, raw, json as json_response
 from sanic.exceptions import InvalidUsage
 
 app = Sanic(__name__)
@@ -389,6 +389,16 @@ async def check_smtp(request):
     return json_response({'status': 'ok', 'helo': helo_domain})
 
 
+@app.route("/robots.txt")
+async def robots(request):
+    return raw(
+        """
+        User-agent: *
+        Disallow: /
+        """
+    )
+
+
 @app.route("/")
 async def main(request):
     return html("You aren't really supposed to use this website using your browser.<br><br>It's a small server with an API to check if a services running on YunoHost instance can be reached from 'the global internet'.")