diff --git a/build.js b/build.js
index 2c6f659..4efb140 100644
--- a/build.js
+++ b/build.js
@@ -4,8 +4,37 @@
 
 import fs from "fs-extra";
 import childProcess from "child_process";
+import path from "path";
 import pkg from "./package.json" with { type: "json" };
 
+/**
+ * Add .js extensions to relative imports in compiled JS files
+ * Required for Node.js ESM module resolution
+ */
+function addJsExtensions(dir) {
+  const files = fs.readdirSync(dir);
+  for (const file of files) {
+    const filePath = path.join(dir, file);
+    const stat = fs.statSync(filePath);
+    if (stat.isDirectory()) {
+      addJsExtensions(filePath);
+    } else if (file.endsWith('.js')) {
+      let content = fs.readFileSync(filePath, 'utf8');
+      // Match: from "./something" or from '../something' (without .js extension)
+      content = content.replace(
+        /(from\s+['"])(\.\.?\/[^'"]+)(?<!\.js)(['"])/g,
+        '$1$2.js$3'
+      );
+      // Match: export * from "./something" or export { x } from '../something'
+      content = content.replace(
+        /(export\s+(?:\*|{[^}]*})\s+from\s+['"])(\.\.?\/[^'"]+)(?<!\.js)(['"])/g,
+        '$1$2.js$3'
+      );
+      fs.writeFileSync(filePath, content);
+    }
+  }
+}
+
 /**
  * Start
  */
@@ -16,6 +45,10 @@ import pkg from "./package.json" with { type: "json" };
     await remove("./dist/");
     await exec("tsc --build tsconfig.prod.json", "./");
 
+    // Add .js extensions to relative imports for Node.js ESM compatibility
+    console.log("Adding .js extensions to imports...");
+    addJsExtensions("./dist");
+
     // Prepare a clean package.json for the published artifact
     const publishPkg = { ...pkg };
 
diff --git a/package.json b/package.json
index 65f2bbc..16c05fd 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@armco/analytics",
-  "version": "0.3.3",
+  "version": "0.3.4",
   "description": "Universal Analytics Library for Browser and Node.js",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",