diff --git a/lib/common/options.js b/lib/common/options.js
index 4a1552d9fd..28ad3a3e2a 100755
--- a/lib/common/options.js
+++ b/lib/common/options.js
@@ -121,6 +121,11 @@ Options.from = function (_options) {
     options.debug = options.dev
   }
 
+  // cssSourceMap
+  if (options.cssSourceMap === undefined) {
+    options.cssSourceMap = options.dev
+  }
+
   // Resolve mode
   let mode = options.mode
   if (typeof mode === 'function') {
@@ -177,7 +182,7 @@ Options.defaults = {
   build: {
     analyze: false,
     extractCSS: false,
-    cssSourceMap: true,
+    cssSourceMap: undefined,
     ssr: undefined,
     publicPath: '/_nuxt/',
     filenames: {