diff --git a/flake.lock b/flake.lock
index d6b2cce..af75e01 100644
--- a/flake.lock
+++ b/flake.lock
@@ -73,11 +73,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1773213477,
-        "narHash": "sha256-Pv1Z3QqGkSGEUV+9pM5vYIiI7VJo7Tfm6ZmR+JSp1zo=",
+        "lastModified": 1778486972,
+        "narHash": "sha256-iuy/TbK9AbghEld2VSFuxyAF30LkOGUUdtrvixLfE7M=",
         "owner": "shazow",
         "repo": "foundry.nix",
-        "rev": "3c73daa86c823d706824fd9bbcb85aa23fd0f668",
+        "rev": "db117ae95a77b9ead24137c3ccb28896ae4fa4ec",
         "type": "github"
       },
       "original": {
@@ -93,11 +93,11 @@
         "nixpkgs": "nixpkgs_2"
       },
       "locked": {
-        "lastModified": 1774104215,
-        "narHash": "sha256-EAtviqz0sEAxdHS4crqu7JGR5oI3BwaqG0mw7CmXkO8=",
+        "lastModified": 1778507602,
+        "narHash": "sha256-kTwur1wV+01SdqskVMSo6JMEpg71ps3HpbFY2GsflKs=",
         "owner": "cachix",
         "repo": "git-hooks.nix",
-        "rev": "f799ae951fde0627157f40aec28dec27b22076d0",
+        "rev": "61ab0e80d9c7ab14c256b5b453d8b3fb0189ba0a",
         "type": "github"
       },
       "original": {
@@ -159,11 +159,11 @@
     },
     "nixpkgs_3": {
       "locked": {
-        "lastModified": 1776017067,
-        "narHash": "sha256-oEp8fqJweZd5doqvH/aBAtc6NzZh+fh0tOhR09gQXck=",
+        "lastModified": 1778656924,
+        "narHash": "sha256-lKVrom9wOmpC3i7m+uBoGaBdW0PfH3QbLRG1XmuC6YA=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "a5a7cf16648d79134eb4da0e3354b08913917b2f",
+        "rev": "4ba039de0909446943c07e2b42bd2f0f4507072e",
         "type": "github"
       },
       "original": {
@@ -190,11 +190,11 @@
     },
     "nixpkgs_5": {
       "locked": {
-        "lastModified": 1771923393,
-        "narHash": "sha256-Fy0+UXELv9hOE8WjYhJt8fMDLYTU2Dqn3cX4BwoGBos=",
+        "lastModified": 1777641297,
+        "narHash": "sha256-WNGcmeOZ8Tr9dq6ztCspYbzWFswr2mPebM9LpsfGxPk=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "ea7f1f06811ce7fcc81d6c6fd4213150c23edcf2",
+        "rev": "c6d65881c5624c9cae5ea6cedef24699b0c0a4c0",
         "type": "github"
       },
       "original": {
@@ -219,11 +219,11 @@
         "nixpkgs": "nixpkgs_4"
       },
       "locked": {
-        "lastModified": 1773216618,
-        "narHash": "sha256-iZlowevS+xKLGOXtZwpIrz3SWe7PtoGUfEeVZNib+WE=",
+        "lastModified": 1778642276,
+        "narHash": "sha256-bhk4lawR4ZnFhPtamB5WkCyvfgyZmsEUbWfT/3FRxFY=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "07d7dc6fcc5eae76b4fb0e19d4afd939437bec97",
+        "rev": "77265d2dc1e61b2abfd3b1d6609dbb66fe75e0a5",
         "type": "github"
       },
       "original": {
@@ -239,11 +239,11 @@
         "solc-macos-amd64-list-json": "solc-macos-amd64-list-json"
       },
       "locked": {
-        "lastModified": 1772085240,
-        "narHash": "sha256-+NEcuhT2A0QQumVx9Ze6g2iuNicyuW028Jq/HUJHGh4=",
+        "lastModified": 1777817996,
+        "narHash": "sha256-iI71iUhD7THLibl3w1JcQEhHmTwZMxChi70RTe33BAo=",
         "owner": "hellwolf",
         "repo": "solc.nix",
-        "rev": "d3cc119973e484ea366f4b997b404bb00d7829ca",
+        "rev": "e3cf898cb804d5c0e5474b378a300fe8942e67d6",
         "type": "github"
       },
       "original": {
@@ -255,13 +255,13 @@
     "solc-macos-amd64-list-json": {
       "flake": false,
       "locked": {
-        "narHash": "sha256-oEiXc95EghuYCudzkPA9XBFOnMdgWFfTO2/4XUfSTpc=",
+        "narHash": "sha256-zzwwHA2qPotv7yp8mK7+y9BZhm7ytuFeCJVvKBBdBn4=",
         "type": "file",
-        "url": "https://github.com/argotorg/solc-bin/raw/83cb756/macosx-amd64/list.json"
+        "url": "https://github.com/argotorg/solc-bin/raw/902dfaf/macosx-amd64/list.json"
       },
       "original": {
         "type": "file",
-        "url": "https://github.com/argotorg/solc-bin/raw/83cb756/macosx-amd64/list.json"
+        "url": "https://github.com/argotorg/solc-bin/raw/902dfaf/macosx-amd64/list.json"
       }
     },
     "systems": {
diff --git a/flake.nix b/flake.nix
index 4edf3d9..c23571e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -42,6 +42,7 @@
         rust-build-inputs = [
           rust-toolchain
           pkgs.cargo-release
+          pkgs.cargo-expand
           pkgs.gmp
           pkgs.openssl
           pkgs.libusb1
@@ -364,8 +365,9 @@
           name = "rust-shell-test";
           body = ''
             bats test/bats/devshell/rust-shell/closure.test.bats
+            bats test/bats/devshell/rust-shell/cargo-expand.test.bats
           '';
-          additionalBuildInputs = [ pkgs.bats ];
+          additionalBuildInputs = [ pkgs.bats ] ++ rust-build-inputs;
         };
 
         pre-commit = git-hooks-nix.lib.${system}.run {
diff --git a/test/bats/devshell/rust-shell/cargo-expand.test.bats b/test/bats/devshell/rust-shell/cargo-expand.test.bats
new file mode 100644
index 0000000..3e4bd9e
--- /dev/null
+++ b/test/bats/devshell/rust-shell/cargo-expand.test.bats
@@ -0,0 +1,4 @@
+@test "cargo expand should be available on PATH" {
+  run cargo expand --version
+  [ "$status" -eq 0 ]
+}