diff --git a/.github/workflows/gpt_pullrequest_updater.yml b/.github/workflows/gpt_pullrequest_updater.yml
index 0fb4d68..0f1184a 100644
--- a/.github/workflows/gpt_pullrequest_updater.yml
+++ b/.github/workflows/gpt_pullrequest_updater.yml
@@ -36,6 +36,7 @@ jobs:
           OWNER: ${{ github.repository_owner }}
           REPO: ${{ github.event.repository.name }}
           PR_NUMBER: ${{ github.event.number }}
+          OPENAI_MODEL: gpt-4
 
       - name: Review Pull Request
         if: github.event.action == 'opened'
@@ -47,3 +48,4 @@ jobs:
           OWNER: ${{ github.repository_owner }}
           REPO: ${{ github.event.repository.name }}
           PR_NUMBER: ${{ github.event.number }}
+          OPENAI_MODEL: gpt-4
diff --git a/cmd/description/main.go b/cmd/description/main.go
index 38a122a..aef8e06 100644
--- a/cmd/description/main.go
+++ b/cmd/description/main.go
@@ -22,6 +22,7 @@ var opts struct {
 	Owner       string `long:"owner" env:"OWNER" description:"GitHub owner" required:"true"`
 	Repo        string `long:"repo" env:"REPO" description:"GitHub repo" required:"true"`
 	PRNumber    int    `long:"pr-number" env:"PR_NUMBER" description:"Pull request number" required:"true"`
+	OpenAIModel string `long:"openai-model" env:"OPENAI_MODEL" description:"OpenAI model" default:"gpt-3.5-turbo"`
 	Test        bool   `long:"test" env:"TEST" description:"Test mode"`
 	JiraURL     string `long:"jira-url" env:"JIRA_URL" description:"Jira URL. Example: https://jira.atlassian.com"`
 }
@@ -43,7 +44,7 @@ func main() {
 }
 
 func run(ctx context.Context) error {
-	openAIClient := oAIClient.NewClient(opts.OpenAIToken)
+	openAIClient := oAIClient.NewClient(opts.OpenAIToken, opts.OpenAIModel)
 	githubClient := ghClient.NewClient(ctx, opts.GithubToken)
 
 	pr, err := githubClient.GetPullRequest(ctx, opts.Owner, opts.Repo, opts.PRNumber)
diff --git a/cmd/review/main.go b/cmd/review/main.go
index 096cfac..74ccde7 100644
--- a/cmd/review/main.go
+++ b/cmd/review/main.go
@@ -20,6 +20,7 @@ var opts struct {
 	Owner       string `long:"owner" env:"OWNER" description:"GitHub owner" required:"true"`
 	Repo        string `long:"repo" env:"REPO" description:"GitHub repo" required:"true"`
 	PRNumber    int    `long:"pr-number" env:"PR_NUMBER" description:"Pull request number" required:"true"`
+	OpenAIModel string `long:"openai-model" env:"OPENAI_MODEL" description:"OpenAI model" default:"gpt-3.5-turbo"`
 	Test        bool   `long:"test" env:"TEST" description:"Test mode"`
 }
 
@@ -40,7 +41,7 @@ func main() {
 }
 
 func run(ctx context.Context) error {
-	openAIClient := oAIClient.NewClient(opts.OpenAIToken)
+	openAIClient := oAIClient.NewClient(opts.OpenAIToken, opts.OpenAIModel)
 	githubClient := ghClient.NewClient(ctx, opts.GithubToken)
 
 	pr, err := githubClient.GetPullRequest(ctx, opts.Owner, opts.Repo, opts.PRNumber)
diff --git a/openai/openai.go b/openai/openai.go
index b21af60..4081ad6 100644
--- a/openai/openai.go
+++ b/openai/openai.go
@@ -21,19 +21,21 @@ var PromptDescribeOverall string
 
 type Client struct {
 	client *openai.Client
+	model  string
 }
 
-func NewClient(token string) *Client {
+func NewClient(token, model string) *Client {
 	return &Client{
 		client: openai.NewClient(token),
+		model:  model,
 	}
 }
 
-func (o *Client) ChatCompletion(ctx context.Context, messages []openai.ChatCompletionMessage) (string, error) {
-	resp, err := o.client.CreateChatCompletion(
+func (c *Client) ChatCompletion(ctx context.Context, messages []openai.ChatCompletionMessage) (string, error) {
+	resp, err := c.client.CreateChatCompletion(
 		ctx,
 		openai.ChatCompletionRequest{
-			Model:       openai.GPT3Dot5Turbo,
+			Model:       c.model,
 			Messages:    messages,
 			Temperature: 0.1,
 		},
@@ -47,10 +49,10 @@ func (o *Client) ChatCompletion(ctx context.Context, messages []openai.ChatCompl
 		fmt.Println("Retrying after 1 minute")
 		// retry once after 1 minute
 		time.Sleep(time.Minute)
-		resp, err = o.client.CreateChatCompletion(
+		resp, err = c.client.CreateChatCompletion(
 			ctx,
 			openai.ChatCompletionRequest{
-				Model:       openai.GPT3Dot5Turbo,
+				Model:       c.model,
 				Messages:    messages,
 				Temperature: 0.1,
 			},