diff --git a/flake.lock b/flake.lock
index ff42753..93c4c70 100644
--- a/flake.lock
+++ b/flake.lock
@@ -51,11 +51,27 @@
         "type": "github"
       }
     },
+    "nixpkgs-unstable": {
+      "locked": {
+        "lastModified": 1651773324,
+        "narHash": "sha256-+tzXzgZQMCxacRmEDRjdbYulorD40BI+YK6aWBwgCcM=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "a1439bc96590dae913369f4515ca3df6ca1a1556",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "flake-utils": "flake-utils",
         "naersk": "naersk",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-unstable": "nixpkgs-unstable"
       }
     }
   },
diff --git a/flake.nix b/flake.nix
index df1aea0..8cb2a0e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,13 +2,15 @@
   description = "A discord bot for Dự Tuyển Tổng Hợp server";
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/21.11";
+    nixpkgs-unstable.url = "github:nixos/nixpkgs";
     naersk.url = "github:nix-community/naersk";
     naersk.inputs.nixpkgs.follows = "nixpkgs";
     flake-utils.url = "github:numtide/flake-utils";
   };
-  outputs = { self, nixpkgs, naersk, flake-utils }: flake-utils.lib.eachDefaultSystem (system:
+  outputs = { self, nixpkgs, nixpkgs-unstable, naersk, flake-utils }: flake-utils.lib.eachDefaultSystem (system:
     let
       pkgs = nixpkgs.legacyPackages."${system}";
+      pkgs-unstable = nixpkgs-unstable.legacyPackages."${system}";
       naersk-lib = naersk.lib."${system}";
     in
     rec {
@@ -38,7 +40,8 @@
       devShell = pkgs.mkShell
         {
           nativeBuildInputs =
-            (with pkgs; [ rustc cargo rust-analyzer rustfmt ])
+            (with pkgs; [ rustc cargo ])
+            ++ (with pkgs-unstable; [ rust-analyzer rustfmt ])
             ++ nixpkgs.lib.optionals (nixpkgs.lib.strings.hasSuffix "darwin" system) (with pkgs; [
               libiconv
               darwin.apple_sdk.frameworks.Security