diff --git a/src/ops.rs b/src/ops.rs
index 8d3444f..103bce0 100644
--- a/src/ops.rs
+++ b/src/ops.rs
@@ -716,7 +716,14 @@ pub fn send(
         .collect();
     let draft = client::SendDraft {
         address: &addr,
-        text: body.to_string(),
+        // Trimmed at the send site, before the payload is signed, so the
+        // signature covers exactly the text the author meant. A compose buffer
+        // ends with whatever the author last pressed, and a trailing newline
+        // is not content — but it is content once it has been signed, and
+        // nothing downstream can remove it without invalidating the
+        // signature. smolboid, for one, refuses a post whose text carries a
+        // line break, because a published record is one line of a feed.
+        text: body.trim().to_string(),
         subject,
         reply_to,
         headers: &owned,