diff --git a/sqlx-core/src/ext/async_stream.rs b/sqlx-core/src/ext/async_stream.rs
index 9afec69f..af368c7b 100644
--- a/sqlx-core/src/ext/async_stream.rs
+++ b/sqlx-core/src/ext/async_stream.rs
@@ -21,7 +21,7 @@ impl<'a, T> TryAsyncStream<'a, T> {
         Fut: 'a + Future<Output = Result<(), Error>> + Send,
         T: 'a + Send,
     {
-        let (mut sender, receiver) = mpsc::channel(1);
+        let (mut sender, receiver) = mpsc::channel(0);
 
         let future = f(sender.clone());
         let future = async move {