diff --git a/book/default.nix b/book/default.nix
index 92ca249..acc543b 100644
--- a/book/default.nix
+++ b/book/default.nix
@@ -42,5 +42,5 @@ in pkgs.dockerTools.buildLayeredImage {
   name = "within/lewa-book";
   tag = version;
   contents = [ nur.repos.xe.quickserv book ];
-  config.Cmd = [ "/bin/quickserv" "-port=9001" "-dir=/book" ];
+  config.Cmd = [ "/bin/quickserv" "--port=9001" "--dir=/book" ];
 }
diff --git a/nix/sources.json b/nix/sources.json
index 4657c50..f9af94c 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -36,15 +36,15 @@
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "nixpkgs": {
-        "branch": "nixpkgs-unstable",
+        "branch": "nixos-20.03",
         "description": "A read-only mirror of NixOS/nixpkgs tracking the released channels. Send issues and PRs to",
         "homepage": "https://github.com/NixOS/nixpkgs",
         "owner": "NixOS",
         "repo": "nixpkgs-channels",
-        "rev": "e23f530858308b9248cfaffb4b99966c0545d4f2",
-        "sha256": "02hjg0zgy0wc6bczsqnqhs4d0gh1idhgdgv114nfkfwlfyx2a2r1",
+        "rev": "93b68c7cc5a4a84f83ee00020bf216a35d645e5e",
+        "sha256": "1yd3ha7zm2hrfmsir152qqkd337r8a1djn98wbvz446qygv20fqh",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs-channels/archive/e23f530858308b9248cfaffb4b99966c0545d4f2.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs-channels/archive/93b68c7cc5a4a84f83ee00020bf216a35d645e5e.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }