diff --git a/AGENTS.md b/AGENTS.md
index f98bf66..bd929ae 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -10,4 +10,5 @@ Keep everything short — replies, explanations, comments, docs.
 - Conventional Commits prefix: `feat:`, `fix:`, `chore:`, `docs:`, `refactor:`, `ci:`, `build:`.
 - Subject as short as possible. Imperative, lowercase, no trailing period.
 - Body only when something genuinely cannot be inferred from the diff.
+- Never add `Co-Authored-By`, "Generated with" or any other AI attribution to commits or PR descriptions.
 - Exception: the commits in `build/upstream` that `patches/` is exported from. Their subjects become the patch file names, so they stay plain and descriptive.
diff --git a/CLAUDE.md b/CLAUDE.md
index a247c34..d7cb269 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -10,4 +10,5 @@ Keep everything short — replies, explanations, comments, docs.
 - Conventional Commits prefix: `feat:`, `fix:`, `chore:`, `docs:`, `refactor:`, `ci:`, `build:`.
 - Subject as short as possible. Imperative, lowercase, no trailing period.
 - Body only when something genuinely cannot be inferred from the diff.
+- Never add `Co-Authored-By`, "Generated with" or any other AI attribution to commits or PR descriptions.
 - Exception: the commits in `build/upstream` that `patches/` is exported from. Their subjects become the patch file names, so they stay plain and descriptive.