diff --git a/packages/vitest/src/node/core.ts b/packages/vitest/src/node/core.ts
index 521649d37..efa95c608 100644
--- a/packages/vitest/src/node/core.ts
+++ b/packages/vitest/src/node/core.ts
@@ -622,7 +622,7 @@ export class Vitest {
       const specifications: TestSpecification[] = []
       for (const file of files) {
         const project = this.getProjectByName(file.projectName || '')
-        const specification = project.createSpecification(file.filepath, undefined, file.pool, file.meta)
+        const specification = project.createSpecification(file.filepath, undefined, file.pool, file.id)
         specifications.push(specification)
       }
 
diff --git a/packages/vitest/src/node/project.ts b/packages/vitest/src/node/project.ts
index 3ff810a69..234bc56a4 100644
--- a/packages/vitest/src/node/project.ts
+++ b/packages/vitest/src/node/project.ts
@@ -1,4 +1,3 @@
-import type { TaskMeta } from '@vitest/runner/types'
 import type { GlobOptions } from 'tinyglobby'
 import type { DevEnvironment, ViteDevServer, InlineConfig as ViteInlineConfig } from 'vite'
 import type { ModuleRunner } from 'vite/module-runner'
@@ -154,14 +153,14 @@ export class TestProject {
     /** @internal */
     pool?: string,
     /** @internal */
-    metaOverride?: TaskMeta,
+    taskIdOverride?: string,
   ): TestSpecification {
     return new TestSpecification(
       this,
       moduleId,
       pool || getFilePoolName(this),
       locationsOrOptions,
-      metaOverride,
+      taskIdOverride,
     )
   }
 
diff --git a/packages/vitest/src/node/test-specification.ts b/packages/vitest/src/node/test-specification.ts
index 133251c34..ccd1e52ba 100644
--- a/packages/vitest/src/node/test-specification.ts
+++ b/packages/vitest/src/node/test-specification.ts
@@ -1,4 +1,3 @@
-import type { TaskMeta } from '@vitest/runner/types'
 import type { SerializedTestSpecification } from '../runtime/types/utils'
 import type { TestProject } from './project'
 import type { TestModule } from './reporters/reported-tasks'
@@ -56,14 +55,14 @@ export class TestSpecification {
     moduleId: string,
     pool: Pool,
     testLinesOrOptions?: number[] | TestSpecificationOptions | undefined,
-    // merge-reports uses the original `file.meta` from the test run
-    metaOverride?: TaskMeta,
+    // merge-reports forces the original task id from the test run
+    taskIdOverride?: string,
   ) {
     const projectName = project.config.name
-    this.taskId = generateFileHash(
+    this.taskId = taskIdOverride ?? generateFileHash(
       relative(project.config.root, moduleId),
       projectName,
-      metaOverride ?? { typecheck: pool === 'typescript', __vitest_label__: project.config.mergeReportsLabel },
+      { typecheck: pool === 'typescript', __vitest_label__: project.config.mergeReportsLabel },
     )
     this.project = project
     this.moduleId = moduleId
diff --git a/test/e2e/test/reporters/merge-reports.test.ts b/test/e2e/test/reporters/merge-reports.test.ts
index 36a29856b..961955bc4 100644
--- a/test/e2e/test/reporters/merge-reports.test.ts
+++ b/test/e2e/test/reporters/merge-reports.test.ts
@@ -2,8 +2,9 @@ import type { RunVitestConfig } from '#test-utils'
 import type { File, Test } from '@vitest/runner/types'
 import type { TestUserConfig, Vitest } from 'vitest/node'
 import type { MergeReport } from 'vitest/src/node/reporters/blob.js'
-import { existsSync, readdirSync, rmSync } from 'node:fs'
+import { cpSync, existsSync, readdirSync, rmSync } from 'node:fs'
 import { mkdir, writeFile } from 'node:fs/promises'
+import path from 'node:path'
 import { buildTestTree, runVitest, useFS } from '#test-utils'
 import { playwright } from '@vitest/browser-playwright'
 import { createFileTask } from '@vitest/runner/utils'
@@ -1026,6 +1027,69 @@ test("top-test", () => {})
   `)
 })
 
+test('onTestRunEnd(testModules) are preserved from different test run roots', async () => {
+  const root1 = resolve(process.cwd(), `vitest-test-${crypto.randomUUID()}`)
+  const root2 = resolve(process.cwd(), `vitest-test-${crypto.randomUUID()}`)
+  useFS(root1, {
+    'basic.test.ts': `test("ok", () => {})`,
+  })
+  useFS(root2, {
+    'basic.test.ts': `test("ok", () => {})`,
+  })
+
+  const result1 = await runVitest({
+    root: root1,
+    globals: true,
+    reporters: [['blob', { label: 'linux' }]],
+  })
+  expect(result1.stderr).toMatchInlineSnapshot(`""`)
+  expect(result1.errorTree()).toMatchInlineSnapshot(`
+    {
+      "basic.test.ts": {
+        "ok": "passed",
+      },
+    }
+  `)
+
+  const result2 = await runVitest({
+    root: root2,
+    globals: true,
+    reporters: [['blob', { label: 'macos' }]],
+  })
+  expect(result2.stderr).toMatchInlineSnapshot(`""`)
+  expect(result2.errorTree()).toMatchInlineSnapshot(`
+    {
+      "basic.test.ts": {
+        "ok": "passed",
+      },
+    }
+  `)
+
+  const blobDir1 = path.join(root1, '.vitest/blob')
+  const blobDir2 = path.join(root2, '.vitest/blob')
+  for (const filename of readdirSync(blobDir2)) {
+    cpSync(path.join(blobDir2, filename), path.join(blobDir1, filename))
+  }
+
+  const result = await runVitest({
+    root: root1,
+    mergeReports: blobDir1,
+  })
+  expect(result.stderr).toMatchInlineSnapshot(`""`)
+  // previously this was "1 passed" due to broken onTestRunEnd(testModules)
+  expect(result.stdout).toContain('Test Files  2 passed')
+  expect(result.errorTree({ fileLabel: true })).toMatchInlineSnapshot(`
+    {
+      "basic.test.ts (linux)": {
+        "ok": "passed",
+      },
+      "basic.test.ts (macos)": {
+        "ok": "passed",
+      },
+    }
+  `)
+})
+
 async function writeBlob(content: MergeReport, filename: string): Promise<void> {
   const report = stringify(content)