diff --git a/tests/vfs/vfs.unit.test.ts b/tests/vfs/vfs.unit.test.ts
index c2f49c9f..cc201de5 100644
--- a/tests/vfs/vfs.unit.test.ts
+++ b/tests/vfs/vfs.unit.test.ts
@@ -396,19 +396,19 @@ describe('VirtualFileSystem - Production Tests', () => {
       await vfs.mkdir('/cached')
       await vfs.writeFile(path, 'cached content')
 
-      // First read (cold cache)
-      const start1 = Date.now()
-      await vfs.readFile(path)
-      const time1 = Date.now() - start1
+      // Prime the path cache + verify the content round-trips.
+      expect((await vfs.readFile(path)).toString()).toBe('cached content')
 
-      // Second read (warm cache)
-      const start2 = Date.now()
-      await vfs.readFile(path)
-      const time2 = Date.now() - start2
+      // Cached repeated access is sub-millisecond. Average many reads so the result
+      // doesn't hinge on Date.now()'s millisecond rounding of a single sub-ms op — the
+      // old cold-vs-warm compare spuriously failed when both rounded to 0/1ms. A
+      // generous absolute bound still catches a regression to per-read disk/index work.
+      const ITERATIONS = 100
+      const start = performance.now()
+      for (let i = 0; i < ITERATIONS; i++) await vfs.readFile(path)
+      const avgWarmMs = (performance.now() - start) / ITERATIONS
 
-      // Cache should make second read faster
-      expect(time2).toBeLessThanOrEqual(time1)
-      console.log(`Cold read: ${time1}ms, Warm read: ${time2}ms`)
+      expect(avgWarmMs).toBeLessThan(5)
     })
   })