diff --git a/lib/options-manager.js b/lib/options-manager.js
index 0c81dc46..3c0759bb 100644
--- a/lib/options-manager.js
+++ b/lib/options-manager.js
@@ -511,6 +511,7 @@ const buildTSConfig = options => config => {
 		config.baseConfig.extends = config.baseConfig.extends.concat('xo-typescript');
 		config.baseConfig.parser = require.resolve('@typescript-eslint/parser');
 		config.baseConfig.parserOptions = {
+			...config.baseConfig.parserOptions,
 			warnOnUnsupportedTypeScriptVersion: false,
 			ecmaFeatures: {jsx: true},
 			project: options.tsConfigPath,
diff --git a/test/options-manager.js b/test/options-manager.js
index b9054e89..b22bc1d9 100644
--- a/test/options-manager.js
+++ b/test/options-manager.js
@@ -436,14 +436,19 @@ test('buildConfig: typescript', t => {
 });
 
 test('buildConfig: typescript with parserOption', t => {
-	const config = manager.buildConfig({ts: true, parserOptions: {projectFolderIgnoreList: []}, tsConfigPath: 'path/to/tmp-tsconfig.json'}, {});
+	const config = manager.buildConfig({
+		ts: true,
+		parserOptions: {projectFolderIgnoreList: [], sourceType: 'script'},
+		tsConfigPath: 'path/to/tmp-tsconfig.json'
+	}, {});
 
 	t.is(config.baseConfig.parser, require.resolve('@typescript-eslint/parser'));
 	t.deepEqual(config.baseConfig.parserOptions, {
 		warnOnUnsupportedTypeScriptVersion: false,
 		ecmaFeatures: {jsx: true},
 		projectFolderIgnoreList: [],
-		project: 'path/to/tmp-tsconfig.json'
+		project: 'path/to/tmp-tsconfig.json',
+		sourceType: 'script'
 	});
 });