diff --git a/examples/chat_completion.rs b/examples/chat_completion.rs
index e4f965b..b87d63d 100644
--- a/examples/chat_completion.rs
+++ b/examples/chat_completion.rs
@@ -6,7 +6,7 @@ use std::env;
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let client = Client::new(env::var("OPENAI_API_KEY").unwrap().to_string());
     let req = ChatCompletionRequest {
-        model: chat_completion::GPT3_5_TURBO.to_string(),
+        model: chat_completion::GPT4.to_string(),
         messages: vec![chat_completion::ChatCompletionMessage {
             role: chat_completion::MessageRole::user,
             content: String::from("NFTとは？"),
diff --git a/src/v1/chat_completion.rs b/src/v1/chat_completion.rs
index d3cfa8f..22330ed 100644
--- a/src/v1/chat_completion.rs
+++ b/src/v1/chat_completion.rs
@@ -4,6 +4,10 @@ use crate::v1::common;
 
 pub const GPT3_5_TURBO: &str = "gpt-3.5-turbo";
 pub const GPT3_5_TURBO_0301: &str = "gpt-3.5-turbo-0301";
+pub const GPT4: &str = "gpt-4";
+pub const GPT4_0314: &str = "gpt-4-0314";
+pub const GPT4_32K: &str = "gpt-4-32k";
+pub const GPT4_32K_0314: &str = "gpt-4-32k-0314";
 
 #[derive(Debug, Serialize)]
 pub struct ChatCompletionRequest {