diff --git a/instances/heimdall/configuration.nix b/instances/heimdall/configuration.nix
index 8df0fc6..e3daa46 100644
--- a/instances/heimdall/configuration.nix
+++ b/instances/heimdall/configuration.nix
@@ -72,6 +72,17 @@ in
   '';
 
   services = {
+    mosquitto = {
+      enable = true;
+      listeners = [{
+        address = "127.0.0.1";
+        port = 1883;
+        users.iotdevice = {
+          acl = [ "pattern readwrite #" ];
+          omitPasswordAuth = true;
+        };
+      }];
+    };
     zigbee2mqtt = {
       enable = true;
       settings = {