diff --git a/README.md b/README.md
index 331a8002..7a5f0e05 100644
--- a/README.md
+++ b/README.md
@@ -65,7 +65,7 @@ $yourApiKey = getenv('YOUR_API_KEY');
 $client = OpenAI::client($yourApiKey);
 
 $result = $client->chat()->create([
-    'model' => 'gpt-4',
+    'model' => 'gpt-4o',
     'messages' => [
         ['role' => 'user', 'content' => 'Hello!'],
     ],
@@ -340,7 +340,7 @@ Creates a streamed completion for the chat message.
 
 ```php
 $stream = $client->chat()->createStreamed([
-    'model' => 'gpt-4',
+    'model' => 'gpt-4o',
     'messages' => [
         ['role' => 'user', 'content' => 'Hello!'],
     ],
@@ -961,7 +961,7 @@ $response = $client->assistants()->create([
             'type' => 'code_interpreter',
         ],
     ],
-    'model' => 'gpt-4',
+    'model' => 'gpt-4o',
 ]);
 
 $response->id; // 'asst_gxzBkD1wkKEloYqZ410pT5pd'
@@ -969,7 +969,7 @@ $response->object; // 'assistant'
 $response->createdAt; // 1623936000
 $response->name; // 'Math Tutor'
 $response->instructions; // 'You are a personal math tutor. When asked a question, write and run Python code to answer the question.'
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->description; // null
 $response->tools[0]->type; // 'code_interpreter'
 $response->toolResources; // []
@@ -993,7 +993,7 @@ $response->object; // 'assistant'
 $response->createdAt; // 1623936000
 $response->name; // 'Math Tutor'
 $response->instructions; // 'You are a personal math tutor. When asked a question, write and run Python code to answer the question.'
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->description; // null
 $response->tools[0]->type; // 'code_interpreter'
 $response->toolResources; // []
@@ -1019,7 +1019,7 @@ $response->object; // 'assistant'
 $response->createdAt; // 1623936000
 $response->name; // 'New Math Tutor'
 $response->instructions; // 'You are a personal math tutor. When asked a question, write and run Python code to answer the question.'
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->description; // null
 $response->tools[0]->type; // 'code_interpreter'
 $response->toolResources; // []
@@ -1121,7 +1121,7 @@ $response->failedAt; // null
 $response->completedAt; // null
 $response->incompleteDetails; // null
 $response->lastError; // null
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->instructions; // null
 $response->tools; // []
 $response->metadata; // []
@@ -1351,7 +1351,7 @@ $response->failedAt; // null
 $response->completedAt; // null
 $response->incompleteDetails; // null
 $response->lastError; // null
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->instructions; // null
 $response->tools; // []
 $response->metadata; // []
@@ -1466,7 +1466,7 @@ $response->failedAt; // null
 $response->completedAt; // null
 $response->incompleteDetails; // null
 $response->lastError; // null
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->instructions; // null
 $response->tools; // []
 $response->metadata; // []
@@ -1512,7 +1512,7 @@ $response->failedAt; // null
 $response->completedAt; // null
 $response->incompleteDetails; // null
 $response->lastError; // null
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->instructions; // null
 $response->tools; // []
 $response->usage->total_tokens; // 579
@@ -1551,7 +1551,7 @@ $response->failedAt; // null
 $response->completedAt; // null
 $response->incompleteDetails; // null
 $response->lastError; // null
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->instructions; // null
 $response->tools; // []
 $response->usage?->total_tokens; // 579
@@ -1598,7 +1598,7 @@ $response->failedAt; // null
 $response->completedAt; // null
 $response->incompleteDetails; // null
 $response->lastError; // null
-$response->model; // 'gpt-4'
+$response->model; // 'gpt-4o'
 $response->instructions; // null
 $response->usage->total_tokens; // 579
 $response->temperature; // null