diff --git a/.circleci/config.yml b/.circleci/config.yml
index fe6cb2e5..3e7c8f4b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -13,6 +13,7 @@ executors:
     environment:
       BUNDLE_PATH: vendor/bundle
       BUNDLE_JOBS: 4
+      BUNDLE_WITHOUT: "development"
     working_directory: ~/app
 
 commands:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 207be02f..93fe0ece 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -9,6 +9,8 @@ jobs:
     timeout-minutes: 5
     permissions:
       contents: write
+    env:
+      BUNDLE_WITHOUT: "development"
 
     steps:
     - uses: actions/checkout@v3
diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index fcb0e3e8..b14d2d20 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -17,6 +17,8 @@ jobs:
     strategy:
       matrix:
         ruby-version: ['3.0', '3.1', '3.2', '3.3.0']
+    env:
+      BUNDLE_WITHOUT: "development"
 
     steps:
     - uses: actions/checkout@v3
diff --git a/.ruby-version b/.ruby-version
index cb2b00e4..ef538c28 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.0.1
+3.1.2
diff --git a/Gemfile b/Gemfile
index c03846e9..0026588d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,12 +10,14 @@ gem "rake"
 gem "rspec"
 gem "rubocop", require: false
 gem "serialport" # シリアル通信をする時に必要。通常はいらない
-gem "sinatra", require: false
-gem "solargraph", "0.50.0", require: false
-gem "stackprof", require: false
 gem "timecop"
-gem "webrick", require: false
-gem "nokogiri", "1.15.5", require: false
+
+group :development do
+  gem "solargraph", "0.50.0", require: false
+  gem "sinatra", require: false
+  gem "stackprof", require: false
+  gem "webrick", require: false
+end
 
 if Gem::Version.new(RUBY_VERSION) > Gem::Version.new("2.6.0")
   gem 'rbs', require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 7aad5ea7..be8b60aa 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -190,7 +190,6 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
-  nokogiri (= 1.15.5)
   procon_bypass_man!
   pry
   rake