diff --git a/storefd-listen/src/lib.rs b/storefd-listen/src/lib.rs
index ff3f60d..249d82b 100644
--- a/storefd-listen/src/lib.rs
+++ b/storefd-listen/src/lib.rs
@@ -230,14 +230,14 @@ impl FileDescriptor {
 
     fn from_fd_offset(fd_offset: usize) -> Result<Self, DupError> {
         SD_LISTEN_FDS_START
-        .checked_add(fd_offset as RawFd)
-        .map(|fd| {
-            // SAFETY: The file descriptor won't be closed by the time we duplicate it.
-            let fd = unsafe { BorrowedFd::borrow_raw(fd) };
-            rustix::fs::fcntl_dupfd_cloexec(fd, 0).map_err(DupError::from)
-        })
-        .expect("Already checked against overflow.")
-        .map(Self::from_fd)
+            .checked_add(fd_offset as RawFd)
+            .map(|fd| {
+                // SAFETY: The file descriptor won't be closed by the time we duplicate it.
+                let fd = unsafe { BorrowedFd::borrow_raw(fd) };
+                rustix::fs::fcntl_dupfd_cloexec(fd, 0).map_err(DupError::from)
+            })
+            .expect("Already checked against overflow.")
+            .map(Self::from_fd)
     }
 
     fn from_fds(
diff --git a/storefd-notify/src/lib.rs b/storefd-notify/src/lib.rs
index 57462c2..d9eeae6 100644
--- a/storefd-notify/src/lib.rs
+++ b/storefd-notify/src/lib.rs
@@ -209,6 +209,7 @@ impl Notifier {
 /// This is created by [`Notifier::guard`].
 ///
 /// Do note that this guard's [`Drop`] implementation will block for the provided timeout and ignore all errors returned by [`barrier()`](Self::barrier).
+#[must_use = "if unused the synchronization will happen immediately"]
 pub struct NotifyBarrierGuard<'a> {
     notifier: &'a Notifier,
     timeout: types::BarrierTimeout,