diff --git a/todo.md b/todo.md
index 1d52854bf..2f942b74a 100644
--- a/todo.md
+++ b/todo.md
@@ -9,3 +9,4 @@
 - webpack warning: lodash too big
 - add coveralls
 - git graph requires a blank line at the end. why?
+- Move cli to mermaid-cli project ?
diff --git a/webpack.config.base.js b/webpack.config.base.js
index ede2ce7d3..0b6cbb87f 100644
--- a/webpack.config.base.js
+++ b/webpack.config.base.js
@@ -17,7 +17,7 @@ export const webConfig = () => {
     entry: {
       mermaid: './src/mermaid.js'
     },
-    externals: 'fs',
+    externals: ['fs'],
     output: {
       path: path.join(__dirname, './dist/'),
       filename: '[name].js'