diff --git a/lib/app-template/default.nix b/lib/app-template/default.nix
index f8302bd..dc92ea5 100644
--- a/lib/app-template/default.nix
+++ b/lib/app-template/default.nix
@@ -2,7 +2,10 @@
   builders,
   fetchers,
   pkgs,
-}: rec {
+}: let
+  bundledATChart = fetchers.helmChart (import ./chart.nix);
+in
+  rec {
   mkImageAttrs = image:
     with builtins; let
       vals = pkgs.lib.strings.splitString ":" image;
@@ -38,13 +41,14 @@
     namespace,
     name,
     mainImage,
+    appTemplateChart ? bundledATChart,
     values ? {},
     kubeVersion ? pkgs.kubernetes.version,
     apiVersions ? [],
   }:
     builders.helmChart {
       inherit name namespace kubeVersion apiVersions;
-      chart = fetchers.helmChart (import ./chart.nix);
+      chart = appTemplateChart;
       values =
         pkgs.lib.attrsets.recursiveUpdate
         {