diff --git a/llm/aicore.go b/llm/aicore.go
index 9527c50..cc3cd45 100644
--- a/llm/aicore.go
+++ b/llm/aicore.go
@@ -276,6 +276,7 @@ func (c *AICoreClient) CompleteAnthropic(ctx context.Context, model string, mess
 	req.Header.Set("Authorization", "Bearer "+token)
 	req.Header.Set("AI-Resource-Group", c.config.ResourceGroup)
 	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("anthropic-version", "2023-06-01")
 
 	resp, err := c.http.Do(req)
 	if err != nil {