@@ -146,6 +146,8 @@ export async function run(
         // mocks should not affect different files
         vi.restoreAllMocks()
         moduleRunner.mocker?.reset()
+        // fake timers patch the worker's `process`, which outlives this file
+        vi.useRealTimers()
       }
     })
   } finally {
 
@@ -0,0 +1,7 @@
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    setupFiles: ['./leave-fake-timers-on.js'],
+  },
+})
@@ -0,0 +1,3 @@
+import { vi } from 'vitest'
+
+vi.useFakeTimers()
@@ -766,6 +766,25 @@ test.for(['vmThreads', 'vmForks'] as const)(
   },
 )
 
+// fake timers also replace `hrtime` on the worker's `process`, which is shared
+// by every file, so files that leave them on must not keep their context alive
+test.for(['vmThreads', 'vmForks'] as const)(
+  '%s releases the vm contexts of files that leave fake timers on',
+  async (pool) => {
+    const { stderr, exitCode } = await runVitestCli(
+      'run',
+      '--root',
+      'fixtures/leak-probe',
+      '--config=./fake-timers.config.js',
+      `--pool=${pool}`,
+      '--environment=./leak-probe-env.ts',
+    )
+
+    expect(stderr).toBe('')
+    expect(exitCode).toBe(0)
+  },
+)
+
 // changing V8 flags at runtime invalidates the module code cache shared across
 // files on a worker: via the context's `node:v8` the cache is cleared up front,
 // via anything else (here the worker realm's binding) the rejection is caught
Original file line number	Diff line number	Diff line change
`@@ -146,6 +146,8 @@ export async function run(`
`146`	`146`	`// mocks should not affect different files`
`147`	`147`	`vi.restoreAllMocks()`
`148`	`148`	`moduleRunner.mocker?.reset()`
	`149`	+ // fake timers patch the worker's `process`, which outlives this file
	`150`	`+ vi.useRealTimers()`
`149`	`151`	`}`
`150`	`152`	`})`
`151`	`153`	`} finally {`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+import { vi } from 'vitest'`
	`2`	`+`
	`3`	`+vi.useFakeTimers()`