diff --git a/test-projects/configs/flat-ts/eslint.config.mjs b/test-projects/configs/flat-ts/eslint.config.mjs
index b7b9b87..16a4960 100644
--- a/test-projects/configs/flat-ts/eslint.config.mjs
+++ b/test-projects/configs/flat-ts/eslint.config.mjs
@@ -23,9 +23,9 @@ import ts from 'typescript-eslint';
 
 import { createRequire } from 'node:module';
 const require = createRequire(import.meta.url);
-const manifestPath = require.resolve('@typescript-eslint/parser/package.json');
+const manifestPath = require.resolve('typescript-eslint/package.json');
 const manifest = require(manifestPath);
-const isV8 = manifest.version[0] > 8;
+const isV8 = parseInt(manifest.version[0]) >= 8;
 
 const parserOptions = {
   esm: {
@@ -34,8 +34,7 @@ const parserOptions = {
       ecmaVersion: 'latest',
     },
     ts: {
-      projectService: true,
-      ...(isV8 ? {} : { project: true }),
+      ...(isV8 ? { project: true } : { projectService: true, project: true }),
       tsconfigRootDir: import.meta.dirname,
     },
   },
diff --git a/test-projects/configs/flat-ts/unpublished-development-types/.gitkeep b/test-projects/configs/flat-ts/unpublished-development-types/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/test-projects/gjs-types/.eslintrc.cjs b/test-projects/gjs-types/.eslintrc.cjs
index 5eb4849..535bd28 100644
--- a/test-projects/gjs-types/.eslintrc.cjs
+++ b/test-projects/gjs-types/.eslintrc.cjs
@@ -15,8 +15,8 @@ const manifestPath = require.resolve('@typescript-eslint/parser/package.json');
 const manifest = require(manifestPath);
 const isV8 = parseInt(manifest.version[0]) >= 8;
 
-if (isV8) {
-  delete parserOptions.project;
+if (isV8 && parserOptions.projectService) {
+  delete parserOptions.projectService;
 }
 
 module.exports = {