diff --git a/build.js b/build.js
index c59b790..0ba5e0f 100644
--- a/build.js
+++ b/build.js
@@ -5,7 +5,7 @@ import * as fs from 'fs'
 
 const serve = process.env.ESBUILD_SERVE === '1'
 const baseurl = process.env.ESBUILD_BASEURL || ''
-const nodeEnv = process.env.NODE_ENV
+const nodeEnv = process.env.NODE_ENV || 'production'
 const isProd = nodeEnv !== 'development'
 
 console.log(`Building with baseurl ${baseurl}`)