diff --git a/package.json b/package.json
index 969a340..9e358ad 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,12 @@
     "test": "eslint bin lib && nyc -r=text -r=lcov mocha",
     "build": "node bin/build.js && node-gyp rebuild"
   },
+  "files": [
+    "*.c",
+    "*.h",
+    "lib",
+    "binding.gyp"
+  ],
   "repository": {
     "type": "git",
     "url": "git+https://github.com/wavedrom/vcd.git"