diff --git a/subprojects/bahaghari/shell.nix b/subprojects/bahaghari/shell.nix
index b21dfbd4..c025b6cd 100644
--- a/subprojects/bahaghari/shell.nix
+++ b/subprojects/bahaghari/shell.nix
@@ -14,6 +14,6 @@ mkShell {
     npins
 
     treefmt
-    nixpkgs-fmt
+    nixfmt-rfc-style
   ];
 }
diff --git a/subprojects/bahaghari/treefmt.toml b/subprojects/bahaghari/treefmt.toml
new file mode 100644
index 00000000..9afb623c
--- /dev/null
+++ b/subprojects/bahaghari/treefmt.toml
@@ -0,0 +1,3 @@
+[formatter.nix]
+command = "nixfmt"
+includes = [ "*.nix" ]