upd

modules/nixos/services/calibre/default.nix

@@ -1,6 +1,7 @@
 {
   config,
   lib,
+  pkgs,
   namespace,
   ...
 }:
@@ -135,6 +136,7 @@ in
       calibre-web = {
         enable = true;
         openFirewall = true;
+        package = pkgs.stable.calibre-web;
         dataDir = cfg.webDir;
         listen = {
           ip = "0.0.0.0";