diff --git a/packages/language-tools/vscode/.vscode-test.js b/packages/language-tools/vscode/.vscode-test.js
deleted file mode 100644
index ea03d3262169..000000000000
--- a/packages/language-tools/vscode/.vscode-test.js
+++ /dev/null
@@ -1,13 +0,0 @@
-const { defineConfig } = require('@vscode/test-cli');
-
-module.exports = defineConfig([
-	{
-		label: 'unitTests',
-		files: 'test/**/*.test.js',
-		version: 'stable',
-		mocha: {
-			ui: 'tdd',
-			timeout: 20000,
-		},
-	},
-]);
diff --git a/packages/language-tools/vscode/.vscode-test.mjs b/packages/language-tools/vscode/.vscode-test.mjs
new file mode 100644
index 000000000000..ce993f0aaac3
--- /dev/null
+++ b/packages/language-tools/vscode/.vscode-test.mjs
@@ -0,0 +1,14 @@
+import { defineConfig } from '@vscode/test-cli';
+
+export default defineConfig([
+	{
+		label: 'unitTests',
+		files: 'test/**/*.test.mts',
+		version: 'stable',
+		mocha: {
+			ui: 'tdd',
+			timeout: 20000,
+			require: ['tsx'],
+		},
+	},
+]);
diff --git a/packages/language-tools/vscode/package.json b/packages/language-tools/vscode/package.json
index 3690e71e38ff..c5e50506dd56 100644
--- a/packages/language-tools/vscode/package.json
+++ b/packages/language-tools/vscode/package.json
@@ -243,7 +243,8 @@
     "test": "pnpm test:vscode && pnpm test:grammar",
     "test:vscode": "vscode-test",
     "test:grammar": "pnpm build:grammar && node ./test/grammar/test.mjs",
-    "update-grammar-snapshots": "node ./test/grammar/test.mjs --updateSnapshot"
+    "update-grammar-snapshots": "node ./test/grammar/test.mjs --updateSnapshot",
+    "typecheck:tests": "tsc --build tsconfig.test.json"
   },
   "devDependencies": {
     "@astrojs/language-server": "^2.16.6",
@@ -262,6 +263,7 @@
     "kleur": "^4.1.5",
     "mocha": "^11.7.5",
     "ovsx": "^0.10.10",
+    "tsx": "^4.21.0",
     "vscode-languageclient": "^9.0.1",
     "vscode-tmgrammar-test": "^0.1.3"
   },
diff --git a/packages/language-tools/vscode/test/extension.test.js b/packages/language-tools/vscode/test/extension.test.mts
similarity index 82%
rename from packages/language-tools/vscode/test/extension.test.js
rename to packages/language-tools/vscode/test/extension.test.mts
index 69b83560c5f5..d27d9ac37fcf 100644
--- a/packages/language-tools/vscode/test/extension.test.js
+++ b/packages/language-tools/vscode/test/extension.test.mts
@@ -1,5 +1,6 @@
-const assert = require('node:assert');
-const vscode = require('vscode');
+import 'mocha';
+import assert from 'node:assert';
+import vscode from 'vscode';
 
 suite('Extension Test Suite', () => {
 	vscode.window.showInformationMessage('Start all tests.');
diff --git a/packages/language-tools/vscode/tsconfig.test.json b/packages/language-tools/vscode/tsconfig.test.json
new file mode 100644
index 000000000000..3ad1bbfc413f
--- /dev/null
+++ b/packages/language-tools/vscode/tsconfig.test.json
@@ -0,0 +1,13 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "include": ["test/**/*.mts", "test/**/*.ts", ".vscode-test.*"],
+  "exclude": ["test/fixtures/**"],
+  "compilerOptions": {
+    "types": ["node"],
+    "allowJs": true,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "rewriteRelativeImportExtensions": true
+  },
+  "references": [{ "path": "../../astro/tsconfig.test.json" }]
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index e025dd418317..0f2b301179e0 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -6772,6 +6772,9 @@ importers:
       ovsx:
         specifier: ^0.10.10
         version: 0.10.10
+      tsx:
+        specifier: ^4.21.0
+        version: 4.21.0
       vscode-languageclient:
         specifier: ^9.0.1
         version: 9.0.1