diff --git a/.eslintrc.cjs b/.eslintrc.cjs
index 19166cf2..e662c0e3 100644
--- a/.eslintrc.cjs
+++ b/.eslintrc.cjs
@@ -238,6 +238,10 @@ module.exports = {
   overrides: [
     {
       files: ['tests/**/*'],
+      parserOptions: {
+        tsconfigRootDir: __dirname,
+        project: ["./tests/tsconfig.json"],
+      },
       extends: ['plugin:vitest/recommended'],
       rules: {
         'import/no-extraneous-dependencies': [
diff --git a/tests/backtrack.test.ts b/tests/backtrack.test.ts
index 4b9bf514..97c0ee44 100644
--- a/tests/backtrack.test.ts
+++ b/tests/backtrack.test.ts
@@ -1,6 +1,6 @@
 import {
-  findFirstSolution,
   type BacktrackOptions,
+  findFirstSolution,
 } from '../src/utils/backtrack';
 
 describe('findFirstSolution', () => {
diff --git a/tests/tsconfig.json b/tests/tsconfig.json
index e2626632..19b70809 100644
--- a/tests/tsconfig.json
+++ b/tests/tsconfig.json
@@ -1,10 +1,10 @@
 {
   "compilerOptions": {
     "target": "ESNext",
-    "module": "CommonJS",
+    "module": "NodeNext",
     "strict": true,
     "lib": ["DOM", "DOM.Iterable", "ESNext"],
     "types": ["vitest/globals"]
   },
-  "include": ["./**/*", "../vitest.config.ts"]
+  "include": ["./**/*", "../vitest.config.mts"]
 }
diff --git a/vitest.config.ts b/vitest.config.mts
similarity index 100%
rename from vitest.config.ts
rename to vitest.config.mts