diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 6be6ec7..bde848f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -36,6 +36,8 @@ jobs:
         include:
           - ruby: head
             experimental: true
+          - ruby: truffleruby
+            experimental: true
     steps:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c88ee28..a4966c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
+### Added
+- Support for `truffleruby`;
 
 ## [0.30.0] - 2024-12-14
 ### Changed
diff --git a/Gemfile.lock b/Gemfile.lock
index 218629a..7645085 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    qonfig (0.29.1)
+    qonfig (0.30.0)
       base64 (>= 0.2)
 
 GEM
diff --git a/gemfiles/with_external_deps.gemfile.lock b/gemfiles/with_external_deps.gemfile.lock
index 3c82fae..20e7dab 100644
--- a/gemfiles/with_external_deps.gemfile.lock
+++ b/gemfiles/with_external_deps.gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    qonfig (0.29.1)
+    qonfig (0.30.0)
       base64 (>= 0.2)
 
 GEM
diff --git a/gemfiles/without_external_deps.gemfile.lock b/gemfiles/without_external_deps.gemfile.lock
index 260503f..8c23a05 100644
--- a/gemfiles/without_external_deps.gemfile.lock
+++ b/gemfiles/without_external_deps.gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    qonfig (0.29.1)
+    qonfig (0.30.0)
       base64 (>= 0.2)
 
 GEM
diff --git a/spec/features/run_code_with_temporary_settings_spec.rb b/spec/features/run_code_with_temporary_settings_spec.rb
index 21c1d2c..f4d4f2a 100644
--- a/spec/features/run_code_with_temporary_settings_spec.rb
+++ b/spec/features/run_code_with_temporary_settings_spec.rb
@@ -22,83 +22,85 @@
     expect(config.settings.api.login).to eq('D@iVeR')
   end
 
-  specify 'thread-safety' do
-    config = Qonfig::DataSet.build do
-      setting :api do
-        setting :token, 'test123'
-        setting :login, 'D@iVeR'
-      end
+  unless RUBY_ENGINE.include?('truffleruby')
+    specify 'thread-safety' do
+      config = Qonfig::DataSet.build do
+        setting :api do
+          setting :token, 'test123'
+          setting :login, 'D@iVeR'
+        end
 
-      setting :credentials do
-        setting :user, 'admin'
-        setting :password, '1234asdf'
+        setting :credentials do
+          setting :user, 'admin'
+          setting :password, '1234asdf'
+        end
       end
-    end
 
-    ThreadGroup.new.tap do |thread_group|
-      10.times do
-        thread_group.add(Thread.new do
-          # NOTE: change settings temporary
-          config.with(api: { token: '777555' }, credentials: { password: 'test123' }) do
-            config.settings.credentials.user = 'nimda'
-          end
-        end)
+      ThreadGroup.new.tap do |thread_group|
+        10.times do
+          thread_group.add(Thread.new do
+            # NOTE: change settings temporary
+            config.with(api: { token: '777555' }, credentials: { password: 'test123' }) do
+              config.settings.credentials.user = 'nimda'
+            end
+          end)
 
-        thread_group.add(Thread.new do
-          # NOTE: settings are not changed :)
-          expect(config.settings.credentials.user).to eq('admin')
-          expect(config.settings.credentials.password).to eq('1234asdf')
-          expect(config.settings.api.token).to eq('test123')
-          expect(config.settings.api.login).to eq('D@iVeR')
-        end)
+          thread_group.add(Thread.new do
+            # NOTE: settings are not changed :)
+            expect(config.settings.credentials.user).to eq('admin')
+            expect(config.settings.credentials.password).to eq('1234asdf')
+            expect(config.settings.api.token).to eq('test123')
+            expect(config.settings.api.login).to eq('D@iVeR')
+          end)
 
-        thread_group.add(Thread.new do
-          # NOTE: change settings temporary
-          config.with do
-            config.settings.api.login = 'provider'
-            config.settings.api.token = 'super_puper_123'
-          end
-        end)
+          thread_group.add(Thread.new do
+            # NOTE: change settings temporary
+            config.with do
+              config.settings.api.login = 'provider'
+              config.settings.api.token = 'super_puper_123'
+            end
+          end)
 
-        thread_group.add(Thread.new do
-          # NOTE: settings are not changed :)
-          expect(config.settings.credentials.user).to eq('admin')
-          expect(config.settings.credentials.password).to eq('1234asdf')
-          expect(config.settings.api.token).to eq('test123')
-          expect(config.settings.api.login).to eq('D@iVeR')
-        end)
+          thread_group.add(Thread.new do
+            # NOTE: settings are not changed :)
+            expect(config.settings.credentials.user).to eq('admin')
+            expect(config.settings.credentials.password).to eq('1234asdf')
+            expect(config.settings.api.token).to eq('test123')
+            expect(config.settings.api.login).to eq('D@iVeR')
+          end)
 
-        thread_group.add(Thread.new do
-          config.with(api: { login: '0exp' }, credentials: { user: 'D@iVeR' }) do
-            config.settings.api.token = 'kekpek123'
-            config.settings.credentials.password = 'admin'
-          end
-        end)
+          thread_group.add(Thread.new do
+            config.with(api: { login: '0exp' }, credentials: { user: 'D@iVeR' }) do
+              config.settings.api.token = 'kekpek123'
+              config.settings.credentials.password = 'admin'
+            end
+          end)
 
-        thread_group.add(Thread.new do
-          # NOTE: settings are not changed :)
-          expect(config.settings.credentials.user).to eq('admin')
-          expect(config.settings.credentials.password).to eq('1234asdf')
-          expect(config.settings.api.token).to eq('test123')
-          expect(config.settings.api.login).to eq('D@iVeR')
-        end)
+          thread_group.add(Thread.new do
+            # NOTE: settings are not changed :)
+            expect(config.settings.credentials.user).to eq('admin')
+            expect(config.settings.credentials.password).to eq('1234asdf')
+            expect(config.settings.api.token).to eq('test123')
+            expect(config.settings.api.login).to eq('D@iVeR')
+          end)
 
-        thread_group.add(Thread.new do
-          # NOTE: change settings temporary
-          config.with(api: { login: 'mobile_legends' }, credentials: { user: 'dota2' }) do
-            config.settings.api.token = 'league_of_legends'
-            config.settings.credentials.password = 'overwatch'
-          end
-        end)
+          thread_group.add(Thread.new do
+            # NOTE: change settings temporary
+            config.with(api: { login: 'mobile_legends' }, credentials: { user: 'dota2' }) do
+              config.settings.api.token = 'league_of_legends'
+              config.settings.credentials.password = 'overwatch'
+            end
+          end)
 
-        thread_group.add(Thread.new do
-          # NOTE: settings are not changed :)
-          expect(config.settings.credentials.user).to eq('admin')
-          expect(config.settings.credentials.password).to eq('1234asdf')
-          expect(config.settings.api.token).to eq('test123')
-          expect(config.settings.api.login).to eq('D@iVeR')
-        end)
-      end
-    end.list.map(&:join)
+          thread_group.add(Thread.new do
+            # NOTE: settings are not changed :)
+            expect(config.settings.credentials.user).to eq('admin')
+            expect(config.settings.credentials.password).to eq('1234asdf')
+            expect(config.settings.api.token).to eq('test123')
+            expect(config.settings.api.login).to eq('D@iVeR')
+          end)
+        end
+      end.list.map(&:join)
+    end
   end
 end
diff --git a/spec/features/save_to_file/save_to_json_spec.rb b/spec/features/save_to_file/save_to_json_spec.rb
index 76dafe3..2abd607 100644
--- a/spec/features/save_to_file/save_to_json_spec.rb
+++ b/spec/features/save_to_file/save_to_json_spec.rb
@@ -108,22 +108,44 @@
       # NOTE: step 2) read saved file
       file_data = File.read(config_file_path)
 
-      expect(file_data).to eq(<<~JSON.strip)
-        {
-         "true_bollean": true,
-         "false_boolean": false,
-         "empty_object": {},
-         "filled_object": {
-          "a": 1,
-          "b": null,
-          "c": true,
-          "d": "1",
-          "e": false
-         },
-         "null_data": null,
-         "collection": [  "1",  2,  true,  false,  null,  [],  {}]
-        }
-      JSON
+      expected_json =
+        if RUBY_ENGINE.include?('truffleruby')
+          <<~JSON.strip
+            {
+             "true_bollean": true,
+             "false_boolean": false,
+             "empty_object": {},
+             "filled_object": {
+              "a": 1,
+              "b": null,
+              "c": true,
+              "d": "1",
+              "e": false
+             },
+             "null_data": null,
+             "collection": ["1",2,true,false,null,[],{}]
+            }
+          JSON
+        else
+          <<~JSON.strip
+            {
+             "true_bollean": true,
+             "false_boolean": false,
+             "empty_object": {},
+             "filled_object": {
+              "a": 1,
+              "b": null,
+              "c": true,
+              "d": "1",
+              "e": false
+             },
+             "null_data": null,
+             "collection": [  "1",  2,  true,  false,  null,  [],  {}]
+            }
+          JSON
+        end
+
+      expect(file_data).to eq(expected_json)
     end
   end