diff --git a/nixos/tsuba/services/aria2.nix b/nixos/tsuba/services/aria2.nix
index 062ca93..5bfc0c8 100644
--- a/nixos/tsuba/services/aria2.nix
+++ b/nixos/tsuba/services/aria2.nix
@@ -1,8 +1,13 @@
 {
   pkgs,
   config,
+  nixpkgs-stable,
   ...
-}: {
+}: let
+  # ariang 1.3.13 fails to build on nixpkgs unstable (broken npm lockfile).
+  # It's a pure static web app, so serve the working 25.11 build.
+  ariang = nixpkgs-stable.legacyPackages.${pkgs.system}.ariang;
+in {
   sops.secrets."aria2/rpc-secret" = {};
 
   services.aria2 = {
@@ -21,12 +26,11 @@
     };
   };
 
-  # AriaNg web UI temporarily disabled: pkgs.ariang fails to build on nixpkgs 26.05.
-  # services.caddy.virtualHosts."aria2.tsuba.darksailor.dev".extraConfig = ''
-  #   import cloudflare
-  #   root * ${pkgs.ariang}/share/ariang
-  #   file_server
-  # '';
+  services.caddy.virtualHosts."aria2.tsuba.darksailor.dev".extraConfig = ''
+    import cloudflare
+    root * ${ariang}/share/ariang
+    file_server
+  '';
   services.caddy.virtualHosts."aria2.tsuba.darksailor.dev:6800".extraConfig = ''
     import cloudflare
     @cors_preflight method OPTIONS