diff --git a/src/client/conn/http2.rs b/src/client/conn/http2.rs
index 9f3c5925bd..5b9e05470c 100644
--- a/src/client/conn/http2.rs
+++ b/src/client/conn/http2.rs
@@ -278,7 +278,7 @@ impl Builder {
/// If not set, hyper will use a default.
///
/// [spec]: https://http2.github.io/http2-spec/#SETTINGS_INITIAL_WINDOW_SIZE
- pub fn http2_initial_stream_window_size(&mut self, sz: impl Into