diff --git a/.husky/commit-msg b/.husky/commit-msg
index c08309a..bb8852e 100644
--- a/.husky/commit-msg
+++ b/.husky/commit-msg
@@ -1 +1,6 @@
+if ! git interpret-trailers --parse "$1" | grep -Eq '^Signed-off-by: .+ <[^<>[:space:]]+>$'; then
+	echo "Commit rejected: add a Signed-off-by trailer with 'git commit -s'." >&2
+	exit 1
+fi
+
 bunx --no -- commitlint --edit "$1"