# must fail: unchanged_two_lines unchanged_blank_line_too
# more than the one session-data line inserted (hls::classical_unchanged)
diff --git a/wai/wai-rs/src/http_binding/hls.rs b/wai/wai-rs/src/http_binding/hls.rs
index 107ae8a1..6a704c25 100644
--- a/wai/wai-rs/src/http_binding/hls.rs
+++ b/wai/wai-rs/src/http_binding/hls.rs
@@ -847,7 +847,7 @@ pub fn classical_unchanged(original: &str, published: &str) -> Result<(), Playli
     let (head, tail) = original.split_at(at);
     let inserted = published.strip_prefix(head).and_then(|r| r.strip_suffix(tail)).ok_or_else(changed)?;
     let bare = inserted.strip_suffix('\n').map(|x| x.strip_suffix('\r').unwrap_or(x)).ok_or_else(changed)?;
-    if bare.contains('\n') || !is_session_data_line(bare) {
+    if !is_session_data_line(bare.lines().next().unwrap_or("")) {
         return Err(changed());
     }
     Ok(())