diff --git a/AGENTS.md b/AGENTS.md
index 767b909..f4751b7 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -94,6 +94,7 @@ SUGGEST commits for full changes
 CHECK syntax before committing
 USE clear and concise commit messages (follow conventional commits if possible)
 NEVER set the git identity
+NEVER add Co-authored-by trailers
 KEEP diffs minimal
 ENSURE small, verifiable commits