diff --git a/flake.nix b/flake.nix
index d58e867..78931df 100644
--- a/flake.nix
+++ b/flake.nix
@@ -52,6 +52,8 @@
 						name = "angestoepselt-site";
 						tag = "latest";
 
+						# See here for the documentation on this option:
+						# https://github.com/moby/moby/blob/master/image/spec/v1.2.md#image-json-field-descriptions
 						config = {
 							Env = [
 								# We need to provide these default variables because otherwise
@@ -59,6 +61,9 @@
 								"ZAMMAD_URL=https://ticket.z31.it"
 								"ZAMMAD_GROUP=testgruppe"
 							];
+							ExposedPorts = {
+								"80/tcp" = {};
+							};
 							Cmd = [
 								"${pkgs.lighttpd}/bin/lighttpd"
 								"-Df"