diff --git a/tools/upend_js/package.json b/tools/upend_js/package.json
index 4308fc5..6bde101 100644
--- a/tools/upend_js/package.json
+++ b/tools/upend_js/package.json
@@ -9,6 +9,11 @@
   },
   "author": "Tomáš Mládek <t@mldk.cz>",
   "license": "MIT",
+  "files": [
+    "*.ts",
+    "*.js",
+    "*.wasm"
+  ],
   "devDependencies": {
     "@types/debug": "^4.1.8",
     "@typescript-eslint/eslint-plugin": "latest",
@@ -17,7 +22,6 @@
     "eslint": "^8.7.0",
     "typescript": "^4.4.4"
   },
-  "packageManager": "yarn@3.1.1",
   "dependencies": {
     "debug": "^4.3.4",
     "lru-cache": "^7.0.0",