diff --git a/default.nix b/default.nix
index 122cef6..9d18537 100644
--- a/default.nix
+++ b/default.nix
@@ -25,7 +25,7 @@ let
       op = attrs: system:
         let
           ret = f system;
-          opt = attrs: key:
+          op = attrs: key:
             attrs //
             {
               ${key} = (attrs.${key} or {}) // { ${system} = ret.${key}; };
diff --git a/example/flake.nix b/example/flake.nix
index d2150e5..d877b0e 100644
--- a/example/flake.nix
+++ b/example/flake.nix
@@ -13,7 +13,7 @@
       rec {
         packages.hello = pkgs.hello;
         defaultPackage = packages.hello;
-        apps.hello = utils.lib.mkApp packages.hello;
+        apps.hello = utils.lib.mkApp { drv = packages.hello; };
         defaultApp = apps.hello;
       }
     );