diff --git a/scripts/test-free-shards.ts b/scripts/test-free-shards.ts
index 4ac9c69cc..4c0bc021e 100755
--- a/scripts/test-free-shards.ts
+++ b/scripts/test-free-shards.ts
@@ -357,6 +357,8 @@ export const TREE_MUTATING: Record<string, string> = {
     'regenerates SKILL.md in place with --respect-detection (gbrain variant), then git-restores — readers see inflated skeletons mid-window',
   'test/host-config.test.ts':
     'golden tests read .agents/.factory artifacts produced by gen-skill-docs.test.ts, and its beforeAll generates them when missing (#2532) — must not race the parallel readers or run before the mutators window',
+  'test/catalog-trim.test.ts':
+    'imports scripts/gen-skill-docs.ts, whose top-level body regenerates the full claude host at import time (71 files; idempotent on a fresh tree, but a stale tree gets rewritten mid-window) — same hazard class as #2532',
   // Ratchet readers (measure the tree; need it quiet):
   'test/parity-suite.test.ts': 'RATCHET READER — parity caps measure live SKILL.md/section bytes',
   'test/skill-size-budget.test.ts': 'RATCHET READER — per-skill and corpus size budgets measure the live tree',