diff --git a/gulp/build.js b/gulp/build.js
index 09a6d44fbc..acad976030 100644
--- a/gulp/build.js
+++ b/gulp/build.js
@@ -21,7 +21,7 @@ const getConfig = prefix => ({
 const genHtml = min =>
     gulp
         .src('templates/*.mustache')
-        .pipe(mustache({}, { extension: '.html' }, getConfig(typeof min === 'boolean' ? '.min' : '')))
+        .pipe(mustache({}, { extension: '.html' }, getConfig(min === true ? '.min' : '')))
         .pipe(gulp.dest('./www'))
         .pipe(connect.reload());