diff --git a/flake.lock b/flake.lock
index e5d0c595b..223ca8348 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1032,6 +1032,22 @@
         "type": "github"
       }
     },
+    "nixpkgs-babel": {
+      "locked": {
+        "lastModified": 1685792587,
+        "narHash": "sha256-SJZySQ1eblQWeNxCU0R7Ly1ZTQOW9A942eNNo/hQq2I=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "39addc620d1585c4d95246f4e47c83467ae3e62a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "39addc620d1585c4d95246f4e47c83467ae3e62a",
+        "type": "github"
+      }
+    },
     "nixpkgs-regression": {
       "locked": {
         "lastModified": 1643052045,
@@ -1342,6 +1358,7 @@
           "haskell-nix",
           "nixpkgs-unstable"
         ],
+        "nixpkgs-babel": "nixpkgs-babel",
         "npmlock2nix": "npmlock2nix",
         "pre-commit-hooks": "pre-commit-hooks",
         "std": "std_2"
diff --git a/flake.nix b/flake.nix
index 24bb0b556..dca3ab3cc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -5,6 +5,7 @@
       url = "github:NixOS/nixpkgs";
       follows = "haskell-nix/nixpkgs-unstable";
     };
+    nixpkgs-babel.url = "github:NixOS/nixpkgs?rev=39addc620d1585c4d95246f4e47c83467ae3e62a";
     haskell-nix = {
       url = "github:input-output-hk/haskell.nix";
       inputs.hackage.follows = "hackage";
diff --git a/nix/cells/marlowe-playground/devshells.nix b/nix/cells/marlowe-playground/devshells.nix
index 8aeb40760..d80833887 100644
--- a/nix/cells/marlowe-playground/devshells.nix
+++ b/nix/cells/marlowe-playground/devshells.nix
@@ -2,6 +2,14 @@
 let
   inherit (cell) library packages scripts;
   inherit (library) pkgs haskell-nix cabal-project;
+  pkgs-babel =
+    if pkgs.nodePackages ? "@babel/cli"
+    then
+      throw "The main nixpkgs input now contains the babel command.\nPlease remove nixpkgs-babel from flake.nix, delete the pkgs-babel definition in devshells.nix, and replace the reference to pkgs-babel.nodePackages.\"@babel-cli\" with pkgs.nodePackages.\"@babel-cli\""
+    else
+      import inputs.nixpkgs-babel {
+        system = pkgs.system;
+      };
   haskell-devshell = haskell-nix.haskellLib.devshellFor cabal-project.shell;
 
   shell = inputs.std.lib.dev.mkShell {
@@ -162,6 +170,15 @@ let
       pkgs.gawk
       pkgs.nil
       pkgs.z3
+      pkgs.yarn
+      pkgs.nodePackages.rimraf
+      pkgs-babel.nodePackages."@babel/cli"
+      pkgs.nodePackages.ts-node
+    ] ++ pkgs.lib.optionals pkgs.stdenv.isLinux [
+      # None of these browsers build on Darwin :(
+      pkgs.chromium
+      pkgs.firefox
+      pkgs.webkitgtk
     ];
 
     devshell.startup."pre-commit-check".text = cell.library.pre-commit-check.shellHook;