diff --git a/Gemfile.lock b/Gemfile.lock
index 6facdc2..0a1d86e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,6 +2,7 @@ PATH
   remote: .
   specs:
     simple_json_schema_builder (0.1.0)
+      multi_json (~> 1.0)
 
 GEM
   remote: https://rubygems.org/
@@ -10,6 +11,7 @@ GEM
     diff-lcs (1.5.1)
     json (2.7.2)
     language_server-protocol (3.17.0.3)
+    multi_json (1.15.0)
     parallel (1.26.3)
     parser (3.3.5.0)
       ast (~> 2.4.1)
diff --git a/lib/simple_json_schema_builder/base.rb b/lib/simple_json_schema_builder/base.rb
index 4e98fcc..d097f03 100644
--- a/lib/simple_json_schema_builder/base.rb
+++ b/lib/simple_json_schema_builder/base.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "multi_json"
+
 module SimpleJsonSchemaBuilder
   class Base
     def self.object(&block)
@@ -12,7 +14,7 @@ def self.schema
     end
 
     def self.to_json
-      schema.to_json
+      MultiJson.dump(schema)
     end
 
     def initialize
diff --git a/simple_json_schema_builder.gemspec b/simple_json_schema_builder.gemspec
index 94ca2d3..cb22b36 100644
--- a/simple_json_schema_builder.gemspec
+++ b/simple_json_schema_builder.gemspec
@@ -10,15 +10,15 @@ Gem::Specification.new do |spec|
 
   spec.summary = "JSON Schema builder with simple DSL."
   spec.description = "Build JSON Schema with simple ruby code, with objects and clean DSL."
-  spec.homepage = "TODO: Put your gem's website or public repo URL here."
+  spec.homepage = "https://github.com/mooktakim/simple_json_schema_builder"
   spec.license = "MIT"
   spec.required_ruby_version = ">= 3.0.0"
 
-  spec.metadata["allowed_push_host"] = "TODO: Set to your gem server 'https://example.com'"
+  # spec.metadata["allowed_push_host"] = "TODO: Set to your gem server 'https://example.com'"
 
   spec.metadata["homepage_uri"] = spec.homepage
-  spec.metadata["source_code_uri"] = "TODO: Put your gem's public repo URL here."
-  spec.metadata["changelog_uri"] = "TODO: Put your gem's CHANGELOG.md URL here."
+  spec.metadata["source_code_uri"] = "https://github.com/mooktakim/simple_json_schema_builder"
+  # spec.metadata["changelog_uri"] = "TODO: Put your gem's CHANGELOG.md URL here."
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
@@ -35,6 +35,7 @@ Gem::Specification.new do |spec|
 
   # Uncomment to register a new dependency of your gem
   # spec.add_dependency "example-gem", "~> 1.0"
+  spec.add_dependency "multi_json", "~> 1.0"
 
   # For more information and examples about making a new gem, check out our
   # guide at: https://bundler.io/guides/creating_gem.html
diff --git a/spec/simple_json_schema_builder/base_spec.rb b/spec/simple_json_schema_builder/base_spec.rb
index 7137ff5..8eaaa41 100644
--- a/spec/simple_json_schema_builder/base_spec.rb
+++ b/spec/simple_json_schema_builder/base_spec.rb
@@ -95,88 +95,98 @@ class TestSubSchema < SimpleJsonSchemaBuilder::Base
   subject { TestSchema.schema }
   let(:properties) { subject[:properties] }
 
-  it "correctly formats schema" do
-    expect(subject[:type]).to eq("object")
-    expect(subject[:required]).to eq(%i[string1 string3 integer1 integer3 number1 number3 boolean1 object1 object3])
-
-    # String
-    expect(properties[:string1][:type]).to eq("string")
-    expect(properties[:string1][:title]).to eq("String1 Title")
-    expect(properties[:string1][:description]).to eq("String1 Description")
-    expect(properties[:string1][:examples]).to eq(["Test1 Example"])
-
-    expect(properties[:string2][:type]).to eq("array")
-    expect(properties[:string2][:items][:type]).to eq("string")
-
-    expect(properties[:string3][:type]).to eq("string")
-    expect(properties[:string3][:enum]).to eq(["Test3 A", "Test3 B"])
-
-    expect(properties[:string4][:type]).to eq("array")
-    expect(properties[:string4][:items][:type]).to eq("string")
-    expect(properties[:string4][:items][:enum]).to eq(["Test4 A", "Test4 B"])
-
-    # Integer
-    expect(properties[:integer1][:type]).to eq("integer")
-    expect(properties[:integer1][:title]).to eq("Integer1 Title")
-    expect(properties[:integer1][:description]).to eq("Integer1 Description")
-    expect(properties[:integer1][:examples]).to eq([1, 2, 3])
-
-    expect(properties[:integer2][:type]).to eq("array")
-    expect(properties[:integer2][:items][:type]).to eq("integer")
-
-    expect(properties[:integer3][:type]).to eq("integer")
-    expect(properties[:integer3][:enum]).to eq([4, 5, 6])
-
-    expect(properties[:integer4][:type]).to eq("array")
-    expect(properties[:integer4][:items][:type]).to eq("integer")
-    expect(properties[:integer4][:items][:enum]).to eq([7, 8, 9])
-
-    # Number
-    expect(properties[:number1][:type]).to eq("number")
-    expect(properties[:number1][:title]).to eq("Number1 Title")
-    expect(properties[:number1][:description]).to eq("Number1 Description")
-    expect(properties[:number1][:examples]).to eq([1, -2, 4])
-
-    expect(properties[:number2][:type]).to eq("array")
-    expect(properties[:number2][:items][:type]).to eq("number")
-
-    expect(properties[:number3][:type]).to eq("number")
-    expect(properties[:number3][:enum]).to eq([1, -1, 4, 1])
-
-    expect(properties[:number4][:type]).to eq("array")
-    expect(properties[:number4][:items][:type]).to eq("number")
-    expect(properties[:number4][:items][:enum]).to eq([-1, -2, -3])
-
-    # Boolean
-    expect(properties[:boolean1][:type]).to eq("boolean")
-    expect(properties[:boolean1][:title]).to eq("Boolean1 Title")
-    expect(properties[:boolean1][:description]).to eq("Boolean1 Description")
-    expect(properties[:boolean1][:examples]).to eq([true, false])
-
-    expect(properties[:boolean2][:type]).to eq("array")
-    expect(properties[:boolean2][:items][:type]).to eq("boolean")
-
-    # Object
-    expect(properties[:object1][:type]).to eq("object")
-    expect(properties[:object1][:properties][:obj_test1][:type]).to eq("string")
-    expect(properties[:object1][:properties][:obj_test2][:type]).to eq("string")
-    expect(properties[:object1][:required]).to eq([:obj_test2])
-
-    expect(properties[:object2][:type]).to eq("array")
-    expect(properties[:object2][:items][:type]).to eq("object")
-    expect(properties[:object2][:items][:properties][:obj_test1][:type]).to eq("string")
-    expect(properties[:object2][:items][:properties][:obj_test2][:type]).to eq("string")
-    expect(properties[:object2][:items][:required]).to eq([:obj_test2])
-
-    expect(properties[:object3][:type]).to eq("object")
-    expect(properties[:object3][:properties][:test1][:type]).to eq("string")
-    expect(properties[:object3][:properties][:test2][:type]).to eq("integer")
-    expect(properties[:object3][:required]).to eq([:test2])
-
-    expect(properties[:object4][:type]).to eq("array")
-    expect(properties[:object4][:items][:type]).to eq("object")
-    expect(properties[:object4][:items][:properties][:test1][:type]).to eq("string")
-    expect(properties[:object4][:items][:properties][:test2][:type]).to eq("integer")
-    expect(properties[:object4][:items][:required]).to eq([:test2])
+  describe ".schema" do
+    it "correctly formats schema" do
+      expect(subject[:type]).to eq("object")
+      expect(subject[:required]).to eq(%i[string1 string3 integer1 integer3 number1 number3 boolean1 object1 object3])
+
+      # String
+      expect(properties[:string1][:type]).to eq("string")
+      expect(properties[:string1][:title]).to eq("String1 Title")
+      expect(properties[:string1][:description]).to eq("String1 Description")
+      expect(properties[:string1][:examples]).to eq(["Test1 Example"])
+
+      expect(properties[:string2][:type]).to eq("array")
+      expect(properties[:string2][:items][:type]).to eq("string")
+
+      expect(properties[:string3][:type]).to eq("string")
+      expect(properties[:string3][:enum]).to eq(["Test3 A", "Test3 B"])
+
+      expect(properties[:string4][:type]).to eq("array")
+      expect(properties[:string4][:items][:type]).to eq("string")
+      expect(properties[:string4][:items][:enum]).to eq(["Test4 A", "Test4 B"])
+
+      # Integer
+      expect(properties[:integer1][:type]).to eq("integer")
+      expect(properties[:integer1][:title]).to eq("Integer1 Title")
+      expect(properties[:integer1][:description]).to eq("Integer1 Description")
+      expect(properties[:integer1][:examples]).to eq([1, 2, 3])
+
+      expect(properties[:integer2][:type]).to eq("array")
+      expect(properties[:integer2][:items][:type]).to eq("integer")
+
+      expect(properties[:integer3][:type]).to eq("integer")
+      expect(properties[:integer3][:enum]).to eq([4, 5, 6])
+
+      expect(properties[:integer4][:type]).to eq("array")
+      expect(properties[:integer4][:items][:type]).to eq("integer")
+      expect(properties[:integer4][:items][:enum]).to eq([7, 8, 9])
+
+      # Number
+      expect(properties[:number1][:type]).to eq("number")
+      expect(properties[:number1][:title]).to eq("Number1 Title")
+      expect(properties[:number1][:description]).to eq("Number1 Description")
+      expect(properties[:number1][:examples]).to eq([1, -2, 4])
+
+      expect(properties[:number2][:type]).to eq("array")
+      expect(properties[:number2][:items][:type]).to eq("number")
+
+      expect(properties[:number3][:type]).to eq("number")
+      expect(properties[:number3][:enum]).to eq([1, -1, 4, 1])
+
+      expect(properties[:number4][:type]).to eq("array")
+      expect(properties[:number4][:items][:type]).to eq("number")
+      expect(properties[:number4][:items][:enum]).to eq([-1, -2, -3])
+
+      # Boolean
+      expect(properties[:boolean1][:type]).to eq("boolean")
+      expect(properties[:boolean1][:title]).to eq("Boolean1 Title")
+      expect(properties[:boolean1][:description]).to eq("Boolean1 Description")
+      expect(properties[:boolean1][:examples]).to eq([true, false])
+
+      expect(properties[:boolean2][:type]).to eq("array")
+      expect(properties[:boolean2][:items][:type]).to eq("boolean")
+
+      # Object
+      expect(properties[:object1][:type]).to eq("object")
+      expect(properties[:object1][:properties][:obj_test1][:type]).to eq("string")
+      expect(properties[:object1][:properties][:obj_test2][:type]).to eq("string")
+      expect(properties[:object1][:required]).to eq([:obj_test2])
+
+      expect(properties[:object2][:type]).to eq("array")
+      expect(properties[:object2][:items][:type]).to eq("object")
+      expect(properties[:object2][:items][:properties][:obj_test1][:type]).to eq("string")
+      expect(properties[:object2][:items][:properties][:obj_test2][:type]).to eq("string")
+      expect(properties[:object2][:items][:required]).to eq([:obj_test2])
+
+      expect(properties[:object3][:type]).to eq("object")
+      expect(properties[:object3][:properties][:test1][:type]).to eq("string")
+      expect(properties[:object3][:properties][:test2][:type]).to eq("integer")
+      expect(properties[:object3][:required]).to eq([:test2])
+
+      expect(properties[:object4][:type]).to eq("array")
+      expect(properties[:object4][:items][:type]).to eq("object")
+      expect(properties[:object4][:items][:properties][:test1][:type]).to eq("string")
+      expect(properties[:object4][:items][:properties][:test2][:type]).to eq("integer")
+      expect(properties[:object4][:items][:required]).to eq([:test2])
+    end
+  end
+
+  describe ".to_json" do
+    it "returns correct JSON" do
+      json = TestSchema.to_json
+      hash = MultiJson.load(json)
+      expect(hash["type"]).to eq("object")
+    end
   end
 end