diff --git a/deploy/install.yml b/deploy/install.yml
index bf88ad4ee768709cfb512d78e893a727df52168c..3b24fd59448ce9382761503f2b70ef7369036e93 100644
--- a/deploy/install.yml
+++ b/deploy/install.yml
@@ -71,6 +71,17 @@
          state: present
          name: rewrite
 
+     # The proxy and proxy-http modules are required to rewrite /.well-known/
+     # requests to the mail server if the file doesn't exist. This is use to
+     # renew Let's Encrypt certificates.
+     - apache2_module:
+         state: present
+         name: proxy
+
+     - apache2_module:
+         state: present
+         name: proxy-http
+
      - name: Install Postfix
        apt:
          pkg: