diff --git a/FORK.md b/FORK.md
index 70609ecc..7e8b0a8b 100644
--- a/FORK.md
+++ b/FORK.md
@@ -10,7 +10,7 @@ as a distant relative.
 ### hyperium
 
 - </~https://github.com/hyperium/h2/tree/v0.4.7>
-- </~https://github.com/hyperium/hyper/tree/v1.5.1>
+- </~https://github.com/hyperium/hyper/tree/v1.5.2>
 - </~https://github.com/hyperium/hyper-util/tree/v0.1.10>
 
 ### tower-r
diff --git a/rama-http-core/src/proto/h1/decode.rs b/rama-http-core/src/proto/h1/decode.rs
index 0bfa0020..6671cc1a 100644
--- a/rama-http-core/src/proto/h1/decode.rs
+++ b/rama-http-core/src/proto/h1/decode.rs
@@ -771,7 +771,7 @@ mod tests {
                 })
                 .await;
                 let desc = format!("read_size failed for {:?}", s);
-                state = result.unwrap_or_else(|_| panic!("{}", desc));
+                state = result.expect(&desc);
                 if state == ChunkedState::Body || state == ChunkedState::EndCr {
                     break;
                 }
diff --git a/rama-http-core/src/proto/h1/io.rs b/rama-http-core/src/proto/h1/io.rs
index be98c4e5..696552f7 100644
--- a/rama-http-core/src/proto/h1/io.rs
+++ b/rama-http-core/src/proto/h1/io.rs
@@ -196,7 +196,11 @@ where
                         return Poll::Ready(Err(crate::Error::new_too_large()));
                     }
                     if curr_len > 0 {
+                        trace!("partial headers; {} bytes so far", curr_len);
                         self.partial_len = Some(curr_len);
+                    } else {
+                        // 1xx gobled some bytes
+                        self.partial_len = None;
                     }
                 }
             }
diff --git a/rama-http-core/src/proto/h1/role.rs b/rama-http-core/src/proto/h1/role.rs
index 9b6248c7..ed925337 100644
--- a/rama-http-core/src/proto/h1/role.rs
+++ b/rama-http-core/src/proto/h1/role.rs
@@ -667,12 +667,14 @@ impl Server {
                             #[cfg(debug_assertions)]
                             {
                                 if let Some(len) = headers::content_length_parse(&value) {
-                                    assert!(
+                                    if msg.req_method != &Some(Method::HEAD) || known_len != 0 {
+                                        assert!(
                                         len == known_len,
                                         "payload claims content-length of {}, custom content-length header claims {}",
                                         known_len,
                                         len,
                                     );
+                                    }
                                 }
                             }
 
diff --git a/rama-http-core/src/proto/h2/ping.rs b/rama-http-core/src/proto/h2/ping.rs
index 4105b6fd..b608c359 100644
--- a/rama-http-core/src/proto/h2/ping.rs
+++ b/rama-http-core/src/proto/h2/ping.rs
@@ -10,14 +10,14 @@
 /// # BDP Algorithm
 ///
 /// 1. When receiving a DATA frame, if a BDP ping isn't outstanding:
-///   - 1a. Record current time.
-///   - 1b. Send a BDP ping.
+///    1a. Record current time.
+///    1b. Send a BDP ping.
 /// 2. Increment the number of received bytes.
 /// 3. When the BDP ping ack is received:
-///   - 3a. Record duration from sent time.
-///   - 3b. Merge RTT with a running average.
-///   - 3c. Calculate bdp as bytes/rtt.
-///   - 3d. If bdp is over 2/3 max, set new max to bdp and update windows.
+///    3a. Record duration from sent time.
+///    3b. Merge RTT with a running average.
+///    3c. Calculate bdp as bytes/rtt.
+///    3d. If bdp is over 2/3 max, set new max to bdp and update windows.
 use std::fmt;
 use std::future::Future;
 use std::pin::Pin;
diff --git a/tests/http-core/client.rs b/tests/http-core/client.rs
index 657f3897..225178ae 100644
--- a/tests/http-core/client.rs
+++ b/tests/http-core/client.rs
@@ -2032,6 +2032,63 @@ mod conn {
         assert_eq!(vec, b"bar=foo");
     }
 
+    #[tokio::test]
+    async fn client_100_then_http09() {
+        let (server, addr) = setup_std_test_server();
+
+        thread::spawn(move || {
+            let mut sock = server.accept().unwrap().0;
+            sock.set_read_timeout(Some(Duration::from_secs(5))).unwrap();
+            sock.set_write_timeout(Some(Duration::from_secs(5)))
+                .unwrap();
+            let mut buf = [0; 4096];
+            let _ = sock.read(&mut buf).expect("read 1");
+            sock.write_all(
+                b"\
+                    HTTP/1.1 100 Continue\r\n\
+                    Content-Type: text/plain\r\n\
+                    Server: BaseHTTP/0.6 Python/3.12.5\r\n\
+                    Date: Mon, 16 Dec 2024 03:08:27 GMT\r\n\
+                ",
+            )
+            .unwrap();
+            // That it's separate writes is important to this test
+            thread::sleep(Duration::from_millis(50));
+            sock.write_all(
+                b"\
+                    \r\n\
+                ",
+            )
+            .expect("write 2");
+            thread::sleep(Duration::from_millis(50));
+            sock.write_all(
+                b"\
+                    This is a sample text/plain document, without final headers.\
+                    \n\n\
+                ",
+            )
+            .expect("write 3");
+        });
+
+        let tcp = tcp_connect(&addr).await.unwrap();
+
+        let (mut client, conn) = conn::http1::Builder::new()
+            .http09_responses(true)
+            .handshake(tcp)
+            .await
+            .unwrap();
+
+        tokio::spawn(async move {
+            let _ = conn.await;
+        });
+
+        let req = Request::builder()
+            .uri("/a")
+            .body(Empty::<Bytes>::new())
+            .unwrap();
+        let _res = client.send_request(req).await.expect("send_request");
+    }
+
     #[tokio::test]
     async fn test_try_send_request() {
         use std::future::Future;
diff --git a/tests/http-core/server.rs b/tests/http-core/server.rs
index 8fcab302..34c0ef91 100644
--- a/tests/http-core/server.rs
+++ b/tests/http-core/server.rs
@@ -1467,7 +1467,7 @@ fn header_name_too_long() {
     let mut req = connect(server.addr());
     let mut write = Vec::with_capacity(1024 * 66);
     write.extend_from_slice(b"GET / HTTP/1.1\r\n");
-    write.resize(1024 * 65 - 1, b'x');
+    write.extend_from_slice(vec![b'x'; 1024 * 64].as_slice());
     write.extend_from_slice(b": foo\r\n\r\n");
     req.write_all(&write).unwrap();