diff --git a/CLAUDE.md b/CLAUDE.md
index 9f2a673c1..4189237e5 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -76,6 +76,7 @@ If user repeats instruction 2+ times, ask: "Should I add this to CLAUDE.md?"
 - Backward Compatibility: 🚨 FORBIDDEN to maintain -- actively remove when encountered
 - Safe Deletion: Use `safeDelete()` from `@socketsecurity/lib/fs` (NEVER `fs.rm/rmSync` or `rm -rf`)
 - HTTP Requests: NEVER use `fetch()` -- use `httpJson`/`httpText`/`httpRequest` from `@socketsecurity/lib/http-request`
+- `Promise.race` / `Promise.any`: NEVER pass a long-lived promise (interrupt signal, pool member) into a race inside a loop. Each call re-attaches `.then` handlers to every arm; handlers accumulate on surviving promises until they settle. For concurrency limiters, use a single-waiter "slot available" signal (resolved by each task's `.then`) instead of re-racing `executing[]`. See nodejs/node#17469 and `@watchable/unpromise`. Race with two fresh arms (e.g. one-shot `withTimeout`) is safe.
 
 ### Documentation Policy