diff --git a/roles/mailman3/files/robots.txt b/roles/mailman3/files/robots.txt
index e97727942b..78ba2efeeb 100644
--- a/roles/mailman3/files/robots.txt
+++ b/roles/mailman3/files/robots.txt
@@ -2,3 +2,4 @@ User-agent: *
 Disallow: /accounts/
 Disallow: /django-admin/
 Disallow: /archives/*/vote$
+Crawl-Delay: 10