diff --git a/CLAUDE.md b/CLAUDE.md
index a4b8e73..f40f8cd 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -41,6 +41,7 @@ Crash artifacts: `lib/fuzz/artifacts/<target>/`. Response validation is in `lib/
 3. **No `unsafe`** in parsing or sanitization paths.
 4. **Validate at the boundary**: Check constraints immediately after deserialization, not deep in business logic.
 5. **Update fuzz assertions**: Tighten the invariant assertions in `lib/src/fuzz_helpers.rs` whenever you add or change a constraint — the fuzzer can only find violations it can check.
+6. We are using our own nusb fork, and API compatibility is not a concern. If an issue is better fixed in nusb, stop and explain the situation.
 
 ## Key architecture