diff --git a/src/lib.rs b/src/lib.rs
index 86c01a3..68e4abb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -67,5 +67,5 @@ pub async fn ask(prompt: &str) -> Result<String, Box<dyn std::error::Error>> {
 
     println!("{:?}", deltas);
 
-    return Ok(deltas[-1].detail.choices[0].delta.content.clone());
+    return Ok(deltas.last().detail.choices[0].delta.content.clone());
 }
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