diff --git a/.github/workflows/rspec.yml b/.github/workflows/rspec.yml
index 5407641..b072daa 100644
--- a/.github/workflows/rspec.yml
+++ b/.github/workflows/rspec.yml
@@ -11,7 +11,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '2.3.1'
+          ruby-version: '3.0.0'
           bundler-cache: true
       - run: gem install bundler -v '< 2.0'
       - run: bundle install
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d8676a7..b6ed8c8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ## Unreleased
 
 - Migrate CI/CD platform from Travis CI to GitHub Actions
+- Requires Ruby 3.0.0 or higher
 
 ## v1.3.5
 
diff --git a/README.md b/README.md
index 42ff77b..a14643c 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ Qiita API v2 client library and CLI tool, written in Ruby.
 
 ## Install
 
-Note: requires Ruby 2.0.0 or higher.
+Note: requires Ruby 3.0.0 or higher.
 
 ```bash
 gem install qiita
diff --git a/lib/qiita/client.rb b/lib/qiita/client.rb
index 31e90d6..251916c 100644
--- a/lib/qiita/client.rb
+++ b/lib/qiita/client.rb
@@ -1,4 +1,3 @@
-require "uri"
 require "qiita/resource_based_methods"
 require "qiita/version"
 
@@ -152,7 +151,7 @@ def process(request_method, path, params, headers)
       Qiita::Response.new(
         connection.send(
           request_method,
-          URI.escape(path),
+          path,
           params,
           headers,
         )
diff --git a/qiita.gemspec b/qiita.gemspec
index ba81bdd..a1845e0 100644
--- a/qiita.gemspec
+++ b/qiita.gemspec
@@ -22,7 +22,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "rainbow"
   spec.add_dependency "rouge"
   spec.add_dependency "slop", "< 4.0.0"
-  spec.add_development_dependency "bundler", "~> 1.6"
+  spec.add_development_dependency "bundler", "~> 2.2"
   spec.add_development_dependency "json_schema"
   spec.add_development_dependency "pry"
   spec.add_development_dependency "rake"
diff --git a/spec/qiita/client_spec.rb b/spec/qiita/client_spec.rb
index f28ca3e..2f94279 100644
--- a/spec/qiita/client_spec.rb
+++ b/spec/qiita/client_spec.rb
@@ -49,7 +49,7 @@ def stub_api_request
   end
 
   let(:client) do
-    described_class.new(options)
+    described_class.new(**options)
   end
 
   let(:options) do
@@ -116,11 +116,7 @@ def stub_api_request
 
   describe ".new" do
     subject do
-      described_class.new(*arguments)
-    end
-
-    let(:arguments) do
-      [options]
+      described_class.new(**options)
     end
 
     let(:options) do
@@ -133,9 +129,9 @@ def stub_api_request
       end
     end
 
-    context "without any arguments" do
-      let(:arguments) do
-        []
+    context "without any options" do
+      let(:options) do
+        {}
       end
       include_examples "returns a Qiita::Client"
     end
@@ -281,7 +277,7 @@ def stub_api_request
       end
 
       let(:requested_url) do
-        "https://#{requested_host}#{URI.escape(path)}"
+        "https://#{requested_host}#{CGI.escape(path)}"
       end
 
       it "sends request with escaped path" do