diff --git a/package.json b/package.json
index 5fbf39b..38e4127 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,12 @@
   "version": "1.5.0",
   "description": "Check if a file is open in another application on Windows, macOS and Linux.",
   "main": "index.js",
+  "files": [
+    "binding.cc",
+    "binding.gyp",
+    "index.js",
+    "test.js"
+  ],
   "repository": {
     "type": "git",
     "url": "git+https://github.com/ronomon/opened.git"