diff --git a/deployment/data-model.nix b/deployment/data-model.nix
index 230e18f1..73d67f32 100644
--- a/deployment/data-model.nix
+++ b/deployment/data-model.nix
@@ -64,7 +64,7 @@ let
     };
   };
   deployment = attrTag {
-    ssh-host = {
+    ssh-host = mkOption {
       description = "A Terraform deployment by SSH to update a single existing NixOS host.";
       type = submodule {
         options = {