diff --git a/tasks/build-npm.ts b/tasks/build-npm.ts
index 34352fd..f078c30 100644
--- a/tasks/build-npm.ts
+++ b/tasks/build-npm.ts
@@ -41,4 +41,7 @@ await build({
     },
     sideEffects: false,
   },
+  async postBuild() {
+    await Deno.copyFile("README.md", `${outDir}/README.md`);
+  },
 });