diff --git a/blog/content/second-edition/posts/12-async-await/index.md b/blog/content/second-edition/posts/12-async-await/index.md
index 7669fc93..cc563b6d 100644
--- a/blog/content/second-edition/posts/12-async-await/index.md
+++ b/blog/content/second-edition/posts/12-async-await/index.md
@@ -191,7 +191,7 @@ struct StringLen<F> {
     inner_future: F,
 }
 
-impl<F> Future for StringLen<F> where Fut: Future<Output = String> {
+impl<F> Future for StringLen<F> where F: Future<Output = String> {
     type Output = usize;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {