diff --git a/ts/index.ts b/ts/index.ts
index 849032b..b83634e 100644
--- a/ts/index.ts
+++ b/ts/index.ts
@@ -25,7 +25,8 @@ const rollupOptions: plugins.rollup.RollupOptions = {
           experimentalDecorators: true,
           inlineSourceMap: true,
           noEmitOnError: true,
-          lib: ['es2016', 'es2017', 'dom'],
+          lib: ['es2017', 'dom'],
+          target: 'es2017',
           noImplicitAny: false
         }
       }