diff --git a/browser/promise.js b/browser/promise.js
deleted file mode 100644
index 06b8309..0000000
--- a/browser/promise.js
+++ /dev/null
@@ -1 +0,0 @@
-export default window.Promise;
diff --git a/rollup.config.browser.js b/rollup.config.browser.js
index adee949..86a0985 100644
--- a/rollup.config.browser.js
+++ b/rollup.config.browser.js
@@ -4,7 +4,6 @@ import config from './rollup.config.js';
 config.plugins.push({
 	load: function ( id ) {
 		if ( ~id.indexOf( 'fs.js' ) ) return readFileSync( 'browser/fs.js' ).toString();
-		if ( ~id.indexOf( 'es6-promise' ) ) return readFileSync( 'browser/promise.js' ).toString();
 	}
 });