diff --git a/Gemfile.lock b/Gemfile.lock
index 087ab77..e0da9d9 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    dotcodegen (0.1.5)
+    dotcodegen (0.1.6)
       dotenv
       front_matter_parser
       ruby-openai
diff --git a/lib/dotcodegen/lint_code.rb b/lib/dotcodegen/lint_code.rb
index 9ca1307..3d0376f 100644
--- a/lib/dotcodegen/lint_code.rb
+++ b/lib/dotcodegen/lint_code.rb
@@ -23,7 +23,6 @@ def run
       end
     end
 
-
     def standardrb_code
       puts "Linting: StandardRB"
       system("standardrb --fix-unsafely #{@file_path}")
diff --git a/lib/dotcodegen/test_code_generator.rb b/lib/dotcodegen/test_code_generator.rb
index 12fbf98..a226e57 100644
--- a/lib/dotcodegen/test_code_generator.rb
+++ b/lib/dotcodegen/test_code_generator.rb
@@ -17,8 +17,9 @@ def initialize(config:, file_to_test_path:, openai_key:, openai_org_id: nil)
     def generate_test_code
       response = openai_client.chat(
         parameters: {
-          model: 'gpt-4-turbo-preview',
+          model: 'gpt-4o',
           messages: [{ role: 'user', content: test_prompt_text }], # Required.
+          response_format: { type: "json_object" },
           temperature: 0.7
         }
       )
diff --git a/lib/dotcodegen/version.rb b/lib/dotcodegen/version.rb
index bc7553b..a13e5bc 100644
--- a/lib/dotcodegen/version.rb
+++ b/lib/dotcodegen/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Dotcodegen
-  VERSION = '0.1.5'
+  VERSION = '0.1.6'
 end