diff --git a/build.js b/build.js
index bf7a5ac..c22eddc 100644
--- a/build.js
+++ b/build.js
@@ -23,3 +23,20 @@ await import('./text.min.js');
 
 const stat = fs.statSync('text.min.js');
 console.info(`text.min.js: ${stat.size}`);
+
+esbuild.buildSync({
+  entryPoints: ['src/ponyfill.js'],
+  bundle: true,
+  format: 'cjs',
+  platform: 'neutral',
+  sourcemap: 'external',
+  outfile: './package/ponyfill.js',
+  target: 'es5',
+  minify: true,
+});
+
+// confirm it imports
+await import('./package/ponyfill.js');
+
+const ponyfillStat = fs.statSync('ponyfill.js');
+console.info(`ponyfill.js: ${ponyfillStat.size}`);
diff --git a/src/ponyfill.js b/src/ponyfill.js
new file mode 100644
index 0000000..0feb824
--- /dev/null
+++ b/src/ponyfill.js
@@ -0,0 +1,2 @@
+export { FastTextEncoder } from './o-encoder.js';
+export { FastTextDecoder } from './o-decoder.js';