diff --git a/modules/openstack_project/files/mailman/robots.txt b/modules/openstack_project/files/mailman/robots.txt
new file mode 100644
index 0000000000..a0ab15bd9c
--- /dev/null
+++ b/modules/openstack_project/files/mailman/robots.txt
@@ -0,0 +1,2 @@
+User-agent: SemrushBot
+Disallow: /
diff --git a/modules/openstack_project/manifests/lists.pp b/modules/openstack_project/manifests/lists.pp
index 5128d6c747..320a591712 100644
--- a/modules/openstack_project/manifests/lists.pp
+++ b/modules/openstack_project/manifests/lists.pp
@@ -8,6 +8,15 @@ class openstack_project::lists(
     multihost => true,
   }
 
+  file { '/var/www/robots.txt':
+    ensure  => present,
+    source  => 'puppet:///modules/openstack_project/mailman/robots.txt',
+    owner   => 'root',
+    group   => 'root',
+    replace => true,
+    mode    => '0444',
+  }
+
   # Disable inactive admins
   user::virtual::disable { 'oubiwann': }
   user::virtual::disable { 'rockstar': }
diff --git a/playbooks/zuul/run-base.yaml b/playbooks/zuul/run-base.yaml
index 560835af08..e6efaceb4e 100644
--- a/playbooks/zuul/run-base.yaml
+++ b/playbooks/zuul/run-base.yaml
@@ -67,6 +67,7 @@
         - host_vars/etherpad01.opendev.org.yaml
         - host_vars/letsencrypt01.opendev.org.yaml
         - host_vars/letsencrypt02.opendev.org.yaml
+        - host_vars/lists.openstack.org.yaml
         - host_vars/gitea99.opendev.org.yaml
         - host_vars/mirror01.openafs.provider.opendev.org.yaml
         - host_vars/mirror-update01.opendev.org.yaml
diff --git a/playbooks/zuul/templates/host_vars/lists.openstack.org.yaml.j2 b/playbooks/zuul/templates/host_vars/lists.openstack.org.yaml.j2
new file mode 100644
index 0000000000..2d38e6c9a3
--- /dev/null
+++ b/playbooks/zuul/templates/host_vars/lists.openstack.org.yaml.j2
@@ -0,0 +1 @@
+listpassword: notarealpassword