diff --git a/devShell.nix b/devShell.nix
index 45c4bb6..919e2d5 100644
--- a/devShell.nix
+++ b/devShell.nix
@@ -67,6 +67,7 @@ devshell.mkShell {
   name = "digga";
   packages = with pkgs; [
     fd
+    treefmt
     alejandra
     # Use the latest stable version of nix
     unstablePkgs.nix
@@ -105,8 +106,8 @@ devshell.mkShell {
     })
     (utils {
       name = "fmt";
-      help = "Check Nix formatting";
-      command = "alejandra \${@} $PRJ_ROOT";
+      help = "Check formatting";
+      command = "treefmt \${@} $PRJ_ROOT";
     })
     (utils {
       name = "evalnix";
diff --git a/examples/devos/profiles/core/common.nix b/examples/devos/profiles/core/common.nix
index beed6bc..9cfca96 100644
--- a/examples/devos/profiles/core/common.nix
+++ b/examples/devos/profiles/core/common.nix
@@ -13,8 +13,7 @@ in
 
     # Selection of sysadmin tools that can come in handy
     systemPackages = with pkgs; [
-      # TODO: must come from unstable channel
-      # alejandra
+      alejandra
       binutils
       coreutils
       curl
diff --git a/examples/devos/shell/devos.nix b/examples/devos/shell/devos.nix
index ea08f0f..5f4e8e8 100644
--- a/examples/devos/shell/devos.nix
+++ b/examples/devos/shell/devos.nix
@@ -35,7 +35,7 @@ in
       help = nvfetcher-bin.meta.description;
       command = "cd $PRJ_ROOT/pkgs; ${nvfetcher-bin}/bin/nvfetcher -c ./sources.toml $@";
     }
-    (linter alejandra)
+    (linter treefmt)
     (linter editorconfig-checker)
 
     (docs mdbook)
diff --git a/examples/devos/shell/hooks/pre-commit.sh b/examples/devos/shell/hooks/pre-commit.sh
index 454289b..4ce4fa1 100755
--- a/examples/devos/shell/hooks/pre-commit.sh
+++ b/examples/devos/shell/hooks/pre-commit.sh
@@ -9,13 +9,12 @@ fi
 
 diff="git diff-index --name-only --cached $against --diff-filter d"
 
-nix_files=($($diff -- '*.nix'))
 all_files=($($diff))
 
-# Format staged nix files.
-if ((${#nix_files[@]} != 0)); then
-  alejandra "${nix_files[@]}" &&
-    git add "${nix_files[@]}"
+# Format staged files.
+if ((${#all_files[@]} != 0)); then
+  treefmt "${all_files[@]}" &&
+    git add "${all_files[@]}"
 fi
 
 # check editorconfig
diff --git a/examples/devos/treefmt.toml b/examples/devos/treefmt.toml
new file mode 100644
index 0000000..fe5d1f3
--- /dev/null
+++ b/examples/devos/treefmt.toml
@@ -0,0 +1,3 @@
+[formatter.nix]
+command = "alejandra"
+includes = ["*.nix"]
diff --git a/flake.nix b/flake.nix
index 8ba130a..93e6130 100644
--- a/flake.nix
+++ b/flake.nix
@@ -144,7 +144,8 @@
       '';
 
       # digga-local use
-      formatter = nixlib.lib.genAttrs supportedSystems (s: nixpkgs.legacyPackages.${s}.alejandra);
+      ## This doesn't appear to be used?
+      formatter = nixlib.lib.genAttrs supportedSystems (s: nixpkgs.legacyPackages.${s}.treefmt);
       # system-space and pass sytem and input to each file
       jobs = polyfillOutput ./jobs;
       checks = polyfillOutput ./checks;
diff --git a/treefmt.toml b/treefmt.toml
new file mode 100644
index 0000000..fe5d1f3
--- /dev/null
+++ b/treefmt.toml
@@ -0,0 +1,3 @@
+[formatter.nix]
+command = "alejandra"
+includes = ["*.nix"]