preserve option for postcss-custom-properties is now a boolean

diff --git a/gulp.d/tasks/build.js b/gulp.d/tasks/build.js
index 4634cf6..cbbb0ca 100644 (file)
--- a/gulp.d/tasks/build.js
+++ b/gulp.d/tasks/build.js
@@ -46,7 +46,7 @@ module.exports = (src, dest, preview) => () => {
         },
       },
     ]),
-    postcssVar({ preserve: preview ? 'preserve-computed' : false }),
+    postcssVar({ preserve: preview }),
     preview ? postcssCalc : () => {},
     autoprefixer,
     preview ? () => {} : cssnano({ preset: 'default' }),