jasmine or mocha 1. Verify Uninstallation: If you've uninstalled @types/jasmine and are still facing the error, it indicates that the duplicate definitions are persisting from another source, likely within your project's node_modules or potentially from a global installation. Here's a systematic approach to pinpoint and resolve the issue. Double-check package.json: Open your package.json file and make absolutely sure @types/jasmine is no longer listed in dependencies or devDependencies. Verify node_modules: Delete the node_modules folder and reinstall your dependencies: Bash rm -rf node_modules npm install This ensures that any lingering cached versions of @types/jasmine are removed. 2. Investigate Remaining Type Definitions: Global Installations (less likely, but possible): While less common, it's possible you have a globally installed package that is causing conflict. Run npm list -g and yarn global list to check for globally installed packages. If you see @types/jasmine or any related packages, uninstall them globally. node_modules Deep Dive: Some dependencies you have may themselves depend on @types/jasmine. Use npm ls @types/jasmine or yarn why @types/jasmine to see if other packages depend on it. If a package is bringing in the offending dependency, you have a few options: Update the package, maybe a newer version removes the dependency. Consider switching to a different library that does not have the problematic dependency. If the offending package is your own, you will need to remove the dependency from it. VS Code Caching: VS Code might be caching type information. Restart VS Code to clear any cached data. 3. Explicitly Scope Definitions (if needed, but still less ideal): If, after all the above, you are still facing the issue, then you may need to explicitly scope the mocha definitions. In the file that is causing the error, import mocha's definitions. TypeScript  import { describe, it, xdescribe } from 'mocha';  describe('Your Suite', () => {  it('Your test', () => {  // your test code.  });  xdescribe('your xdescribe', ()=>{  //your skipped test.  });  }); This will force the file to use the imported mocha definitions, and should resolve the conflict.