diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0b15608..067efb5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -46,6 +46,8 @@ jobs:
           ruby-version: '3.2'
       - name: Setup Rust
         uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
       - name: Install Ruby dependencies
         run: bundle install
       - name: Setup just
diff --git a/flake.lock b/flake.lock
index 15a9d58..ed36340 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,5 +1,26 @@
 {
   "nodes": {
+    "fenix": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "rust-analyzer-src": "rust-analyzer-src"
+      },
+      "locked": {
+        "lastModified": 1754462708,
+        "narHash": "sha256-82koJGbd4Z2fkoKRahRrSQY/lHjrXuMvsyUC65+cphU=",
+        "owner": "nix-community",
+        "repo": "fenix",
+        "rev": "411d129fad840043f724f98719706be39aa7de9c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "fenix",
+        "type": "github"
+      }
+    },
     "flake-compat": {
       "flake": false,
       "locked": {
@@ -91,9 +112,27 @@
     },
     "root": {
       "inputs": {
+        "fenix": "fenix",
         "nixpkgs": "nixpkgs",
         "pre-commit-hooks": "pre-commit-hooks"
       }
+    },
+    "rust-analyzer-src": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1754428884,
+        "narHash": "sha256-a+hFq6zFCDhGrW7yK9le4Do80dbQIaYS0ijpOY53i7A=",
+        "owner": "rust-lang",
+        "repo": "rust-analyzer",
+        "rev": "75436532df916b370552652b4df601273e518025",
+        "type": "github"
+      },
+      "original": {
+        "owner": "rust-lang",
+        "ref": "nightly",
+        "repo": "rust-analyzer",
+        "type": "github"
+      }
     }
   },
   "root": "root",
diff --git a/flake.nix b/flake.nix
index 37abe1b..c3ba90c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,16 +1,28 @@
 {
   description = "Development environment for codetracer-ruby-recorder";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
-  inputs.pre-commit-hooks.url = "github:cachix/git-hooks.nix";
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+    fenix = {
+      url = "github:nix-community/fenix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    pre-commit-hooks.url = "github:cachix/git-hooks.nix";
+  };
 
   outputs = {
     self,
     nixpkgs,
+    fenix,
     pre-commit-hooks,
   }: let
     systems = ["x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin"];
     forEachSystem = nixpkgs.lib.genAttrs systems;
+
+    rust-toolchain-for = system: fenix.packages.${system}.fromToolchainFile {
+      file = ./rust-toolchain.toml;
+      sha256 = "sha256-Qxt8XAuaUR2OMdKbN4u8dBJOhSHxS+uS06Wl9+flVEk=";
+    };
   in {
     checks = forEachSystem (system: {
       pre-commit-check = pre-commit-hooks.lib.${system}.run {
@@ -38,8 +50,7 @@
           ruby
 
           # The native extension is implemented in Rust
-          rustc
-          cargo
+          (rust-toolchain-for system)
           libiconv # Required dependency when building the rb-sys Rust crate on macOS and some Linux systems
 
           # Required for bindgen (used by rb-sys crate for generating Ruby C API bindings)
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 100644
index 0000000..5913d1c
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1,3 @@
+[toolchain]
+channel = "1.88.0"
+components = [ "rustc", "rust-analyzer", "rust-std", "cargo", "rustfmt", "rustc-dev", "llvm-tools" ]