diff --git a/config/common/acme.nix b/config/common/acme.nix
new file mode 100644
index 0000000..ce9d6d8
--- /dev/null
+++ b/config/common/acme.nix
@@ -0,0 +1,13 @@
+# Common ACME configuration.
+# Sources for this configuration:
+# - https://nixos.org/manual/nixos/stable/#module-security-acme
+# - https://git.grzb.de/yuri/nix-infra/-/blob/aa38daeea59f2ca12b7e591de6f8b61565780c48/configuration/common/default.nix#L48
+
+{ config, pkgs, ... }:
+
+{
+  security.acme = {
+    acceptTerms = true;
+    defaults.email = "julian+nix-infra-cccchh-letsencrypt@jsts.xyz";
+  };
+}
diff --git a/config/common/default.nix b/config/common/default.nix
index d1584eb..76bece1 100644
--- a/config/common/default.nix
+++ b/config/common/default.nix
@@ -2,6 +2,7 @@
 
 {
   imports = [
+    ./acme.nix
     ./default-host-platform.nix
     ./default-state-version.nix
     ./localization.nix