diff --git a/extensions/postinstall.mjs b/extensions/postinstall.mjs
index 04e54dd6e2c..f073aa720c9 100644
--- a/extensions/postinstall.mjs
+++ b/extensions/postinstall.mjs
@@ -26,7 +26,10 @@ function processRoot() {
 function processLib() {
 	const toDelete = new Set([
 		'tsc.js',
+		'_tsc.js',
+
 		'typescriptServices.js',
+		'_typescriptServices.js',
 	]);
 
 	const libRoot = path.join(root, 'lib');