diff --git a/packages/vitest/src/node/core.ts b/packages/vitest/src/node/core.ts
index fe9f4e36fd70..8a0508f50039 100644
--- a/packages/vitest/src/node/core.ts
+++ b/packages/vitest/src/node/core.ts
@@ -203,6 +203,7 @@ export class Vitest {
     this._workspaceConfigPath = undefined
     this.coverageProvider = undefined
     this.runningPromise = undefined
+    this.coreWorkspaceProject = undefined
     this.specifications.clearCache()
     this._onUserTestsRerun = []
 
diff --git a/packages/vitest/src/node/project.ts b/packages/vitest/src/node/project.ts
index 3be74e3e006b..213d23f43222 100644
--- a/packages/vitest/src/node/project.ts
+++ b/packages/vitest/src/node/project.ts
@@ -491,10 +491,8 @@ export class TestProject {
     return testFiles
   }
 
-  /** @internal */
-  _parentBrowser?: ParentProjectBrowser
-  /** @internal */
-  _parent?: TestProject
+  private _parentBrowser?: ParentProjectBrowser
+  private _parent?: TestProject
   /** @internal */
   _initParentBrowser = deduped(async () => {
     if (!this.isBrowserEnabled() || this._parentBrowser) {