diff --git a/crates/anthropic/src/anthropic.rs b/crates/anthropic/src/anthropic.rs
index 773bb557de1895e57bdeb5612e01e2839af3244b..7fd0fb4bc5abd983c57507522c2a37dffcbfa258 100644
--- a/crates/anthropic/src/anthropic.rs
+++ b/crates/anthropic/src/anthropic.rs
@@ -363,11 +363,9 @@ pub async fn complete(
     api_url: &str,
     api_key: &str,
     request: Request,
+    beta_headers: String,
 ) -> Result<Response, AnthropicError> {
     let uri = format!("{api_url}/v1/messages");
-    let beta_headers = Model::from_id(&request.model)
-        .map(|model| model.beta_headers())
-        .unwrap_or_else(|_| Model::DEFAULT_BETA_HEADERS.join(","));
     let request_builder = HttpRequest::builder()
         .method(Method::POST)
         .uri(uri)
@@ -409,8 +407,9 @@ pub async fn stream_completion(
     api_url: &str,
     api_key: &str,
     request: Request,
+    beta_headers: String,
 ) -> Result<BoxStream<'static, Result<Event, AnthropicError>>, AnthropicError> {
-    stream_completion_with_rate_limit_info(client, api_url, api_key, request)
+    stream_completion_with_rate_limit_info(client, api_url, api_key, request, beta_headers)
         .await
         .map(|output| output.0)
 }
@@ -506,6 +505,7 @@ pub async fn stream_completion_with_rate_limit_info(
     api_url: &str,
     api_key: &str,
     request: Request,
+    beta_headers: String,
 ) -> Result<
     (
         BoxStream<'static, Result<Event, AnthropicError>>,
@@ -518,9 +518,7 @@ pub async fn stream_completion_with_rate_limit_info(
         stream: true,
     };
     let uri = format!("{api_url}/v1/messages");
-    let beta_headers = Model::from_id(&request.base.model)
-        .map(|model| model.beta_headers())
-        .unwrap_or_else(|_| Model::DEFAULT_BETA_HEADERS.join(","));
+
     let request_builder = HttpRequest::builder()
         .method(Method::POST)
         .uri(uri)
diff --git a/crates/language_models/src/provider/anthropic.rs b/crates/language_models/src/provider/anthropic.rs
index 6c003c4c3919a9f553024c6b1b56d03d410d984b..d246976cda4eb46a46c857f1e94757697ddf5f65 100644
--- a/crates/language_models/src/provider/anthropic.rs
+++ b/crates/language_models/src/provider/anthropic.rs
@@ -424,14 +424,21 @@ impl AnthropicModel {
             return futures::future::ready(Err(anyhow!("App state dropped").into())).boxed();
         };
 
+        let beta_headers = self.model.beta_headers();
+
         async move {
             let Some(api_key) = api_key else {
                 return Err(LanguageModelCompletionError::NoApiKey {
                     provider: PROVIDER_NAME,
                 });
             };
-            let request =
-                anthropic::stream_completion(http_client.as_ref(), &api_url, &api_key, request);
+            let request = anthropic::stream_completion(
+                http_client.as_ref(),
+                &api_url,
+                &api_key,
+                request,
+                beta_headers,
+            );
             request.await.map_err(Into::into)
         }
         .boxed()