diff --git a/roles/matrix-nginx-proxy/defaults/main.yml b/roles/matrix-nginx-proxy/defaults/main.yml
index e3c19d86..3bb2723d 100644
--- a/roles/matrix-nginx-proxy/defaults/main.yml
+++ b/roles/matrix-nginx-proxy/defaults/main.yml
@@ -437,7 +437,7 @@ matrix_ssl_additional_domains_to_obtain_certificates_for: []
 
 # Controls whether to obtain production or staging certificates from Let's Encrypt.
 matrix_ssl_lets_encrypt_staging: false
-matrix_ssl_lets_encrypt_certbot_docker_image: "{{ matrix_container_global_registry_prefix }}certbot/certbot:{{ matrix_ssl_architecture }}-v1.20.0"
+matrix_ssl_lets_encrypt_certbot_docker_image: "{{ matrix_container_global_registry_prefix }}certbot/certbot:{{ matrix_ssl_architecture }}-v1.21.0"
 matrix_ssl_lets_encrypt_certbot_docker_image_force_pull: "{{ matrix_ssl_lets_encrypt_certbot_docker_image.endswith(':latest') }}"
 matrix_ssl_lets_encrypt_certbot_standalone_http_port: 2402
 matrix_ssl_lets_encrypt_support_email: ~