diff --git a/nix/sources.json b/nix/sources.json
index 9c917ddb..b8917c1a 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -110,10 +110,10 @@
         "homepage": null,
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "fcd48a5a0693f016a5c370460d0c2a8243b882dc",
-        "sha256": "06nyvac1azpa9gqdhj9py6ljsvbfgx49ilp8kf6w0w9clxba64vg",
+        "rev": "73ad5f9e147c0d2a2061f1d4bd91e05078dc0b58",
+        "sha256": "01j7nhxbb2kjw38yk4hkjkkbmz50g3br7fgvad6b1cjpdvfsllds",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/fcd48a5a0693f016a5c370460d0c2a8243b882dc.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/73ad5f9e147c0d2a2061f1d4bd91e05078dc0b58.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "obelisk": {
diff --git a/overlays/10-previews.nix b/overlays/10-previews.nix
index eaed20cf..b28f48e0 100644
--- a/overlays/10-previews.nix
+++ b/overlays/10-previews.nix
@@ -5,9 +5,8 @@ in {
   nix = self.nix_2_4;
   unstableHaskellPackages = unstable.haskellPackages;
   unstableGhc = unstable.ghc;
-  inherit (unstable) home-assistant vscode-extensions vscode mumble cachix cabal2nix;
-  nix-output-monitor = unstable.haskell.lib.overrideCabal (unstable.haskellPackages.callCabal2nix "nix-output-monitor" super.sources.nix-output-monitor {}) {
-    inherit (super.nix-output-monitor) postInstall;
-    doCheck = false;
+  inherit (unstable) home-assistant vscode-extensions vscode mumble cachix cabal2nix alejandra;
+  nix-output-monitor = super.haskell.lib.overrideCabal unstable.nix-output-monitor {
+    src = super.sources.nix-output-monitor;
   };
 }
diff --git a/overlays/pkgSets.nix b/overlays/pkgSets.nix
index 67480ca1..d753f67d 100644
--- a/overlays/pkgSets.nix
+++ b/overlays/pkgSets.nix
@@ -152,6 +152,7 @@ self: super: {
       tasksh
       magic-wormhole
       rnix-lsp
+      alejandra
       rustup
       nix-top
       ghcWithPackages