diff --git a/README.md b/README.md
index 30b7644..3bba7ef 100644
--- a/README.md
+++ b/README.md
@@ -37,7 +37,7 @@ message = client.messages.create(
             "content": "Hello, Claude",
         }
     ],
-    model="claude-3-opus-20240229",
+    model="claude-3-5-sonnet-latest",
 )
 print(message.content)
 ```
@@ -70,7 +70,7 @@ async def main() -> None:
                 "content": "Hello, Claude",
             }
         ],
-        model="claude-3-opus-20240229",
+        model="claude-3-5-sonnet-latest",
     )
     print(message.content)
 
@@ -97,7 +97,7 @@ stream = client.messages.create(
             "content": "Hello, Claude",
         }
     ],
-    model="claude-3-opus-20240229",
+    model="claude-3-5-sonnet-latest",
     stream=True,
 )
 for event in stream:
@@ -119,7 +119,7 @@ stream = await client.messages.create(
             "content": "Hello, Claude",
         }
     ],
-    model="claude-3-opus-20240229",
+    model="claude-3-5-sonnet-latest",
     stream=True,
 )
 async for event in stream:
@@ -230,7 +230,7 @@ try:
                 "content": "Hello, Claude",
             }
         ],
-        model="claude-3-opus-20240229",
+        model="claude-3-5-sonnet-latest",
     )
 except anthropic.APIConnectionError as e:
     print("The server could not be reached")
@@ -282,7 +282,7 @@ client.with_options(max_retries=5).messages.create(
             "content": "Hello, Claude",
         }
     ],
-    model="claude-3-opus-20240229",
+    model="claude-3-5-sonnet-latest",
 )
 ```
 
@@ -314,7 +314,7 @@ client.with_options(timeout=5.0).messages.create(
             "content": "Hello, Claude",
         }
     ],
-    model="claude-3-opus-20240229",
+    model="claude-3-5-sonnet-latest",
 )
 ```
 
@@ -378,7 +378,7 @@ response = client.messages.with_raw_response.create(
         "role": "user",
         "content": "Hello, Claude",
     }],
-    model="claude-3-opus-20240229",
+    model="claude-3-5-sonnet-latest",
 )
 print(response.headers.get('X-My-Header'))
 
@@ -412,7 +412,7 @@ with client.messages.with_streaming_response.create(
             "content": "Hello, Claude",
         }
     ],
-    model="claude-3-opus-20240229",
+    model="claude-3-5-sonnet-latest",
 ) as response:
     print(response.headers.get("X-My-Header"))
 
diff --git a/tests/test_client.py b/tests/test_client.py
index f50233f..ca181ad 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -745,7 +745,7 @@ def test_retrying_timeout_errors_doesnt_leak(self, respx_mock: MockRouter) -> No
                                 "content": "Hello, Claude",
                             }
                         ],
-                        model="claude-3-opus-20240229",
+                        model="claude-3-5-sonnet-latest",
                     ),
                 ),
                 cast_to=httpx.Response,
@@ -772,7 +772,7 @@ def test_retrying_status_errors_doesnt_leak(self, respx_mock: MockRouter) -> Non
                                 "content": "Hello, Claude",
                             }
                         ],
-                        model="claude-3-opus-20240229",
+                        model="claude-3-5-sonnet-latest",
                     ),
                 ),
                 cast_to=httpx.Response,
@@ -1625,7 +1625,7 @@ async def test_retrying_timeout_errors_doesnt_leak(self, respx_mock: MockRouter)
                                 "content": "Hello, Claude",
                             }
                         ],
-                        model="claude-3-opus-20240229",
+                        model="claude-3-5-sonnet-latest",
                     ),
                 ),
                 cast_to=httpx.Response,
@@ -1652,7 +1652,7 @@ async def test_retrying_status_errors_doesnt_leak(self, respx_mock: MockRouter)
                                 "content": "Hello, Claude",
                             }
                         ],
-                        model="claude-3-opus-20240229",
+                        model="claude-3-5-sonnet-latest",
                     ),
                 ),
                 cast_to=httpx.Response,