diff --git a/.npmignore b/.npmignore
deleted file mode 100644
index 2f38c9a619..0000000000
--- a/.npmignore
+++ /dev/null
@@ -1,4 +0,0 @@
-test/
-util/
-img/
-\..*
diff --git a/package.json b/package.json
index 8c52e47cc8..96cebb1a13 100644
--- a/package.json
+++ b/package.json
@@ -64,5 +64,12 @@
   },
   "dependencies": {
     "@webcomponents/shadycss": "^1.2.0"
-  }
+  },
+  "files": [
+    "externs",
+    "lib",
+    "index.html",
+    "polymer-*.js",
+    "manifest.json"
+  ]
 }