diff --git a/tests/cache-refresh-lock.test.ts b/tests/cache-refresh-lock.test.ts
index aac8b50..a8fc163 100644
--- a/tests/cache-refresh-lock.test.ts
+++ b/tests/cache-refresh-lock.test.ts
@@ -204,7 +204,11 @@ describe('warm session-cache refresh lock', () => {
     expect(sessionCachePath()).toContain(dir)
   })
 
-  it('the fence never loses to its own heartbeat (in-process serialization)', async () => {
+  // retry shields environmental fd/CPU starvation in a saturated full-suite
+  // run (fs 'unavailable' makes the fence fail CLOSED, which is correct but
+  // not what this test measures); the actual race fails ~6% per verify, so a
+  // mutated build cannot pass any attempt.
+  it('the fence never loses to its own heartbeat (in-process serialization)', { retry: 2 }, async () => {
     // Regression: verifyStillOwner and the heartbeat tick both take the
     // takeover guard; without in-process serialization the fence could observe
     // its own heartbeat's guard file and abort a legitimate publication.