diff --git a/src/cli.js b/src/cli.js
index 6bde994d052..242095c25db 100755
--- a/src/cli.js
+++ b/src/cli.js
@@ -174,7 +174,7 @@ async function bundle(main, command) {
   const Bundler = require('../');
 
   if (command.name() === 'build') {
-    process.env.NODE_ENV = 'production';
+    process.env.NODE_ENV = process.env.NODE_ENV || 'production';
   } else {
     process.env.NODE_ENV = process.env.NODE_ENV || 'development';
   }