diff --git a/Gemfile.lock b/Gemfile.lock
index 1a3c7b7..ab86aa3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -54,7 +54,7 @@ GEM
       nokogiri (~> 1.12)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    json (2.6.3)
+    json (2.7.1)
     json-minify (0.0.3)
       json (> 0)
     kramdown (2.4.0)
diff --git a/gemset.nix b/gemset.nix
index 5ea38d9..55b4032 100644
--- a/gemset.nix
+++ b/gemset.nix
@@ -235,10 +235,10 @@
     platforms = [];
     source = {
       remotes = ["https://rubygems.org"];
-      sha256 = "0nalhin1gda4v8ybk6lq8f407cgfrj6qzn234yra4ipkmlbfmal6";
+      sha256 = "0r9jmjhg2ly3l736flk7r2al47b5c8cayh0gqkq0yhjqzc9a6zhq";
       type = "gem";
     };
-    version = "2.6.3";
+    version = "2.7.1";
   };
   json-minify = {
     dependencies = ["json"];
diff --git a/shell.nix b/shell.nix
index c6fa7c6..269d4fd 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,4 +1,16 @@
-{ pkgs ? import <nixpkgs> {} }:
-  pkgs.mkShell {
-    nativeBuildInputs = with pkgs.buildPackages; [ bundler nodejs-slim bundix ];
+{ pkgs ? import <nixpkgs> { } }:
+pkgs.mkShell {
+  nativeBuildInputs = with pkgs.buildPackages;
+    with rubyPackages; [
+      bundler
+      nodejs-slim
+      bundix
+      jekyll
+      bundler
+      eventmachine
+      racc
+      em-websocket
+      ffi
+      json
+    ];
 }