diff --git a/gulpfile.js b/gulpfile.js
index c350a544..ca22211f 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -302,6 +302,7 @@ gulp.task('serve', () => {
     gulp.watch([
         slidesRoot + '**/*.html', 
         slidesRoot + '**/*.md',
+        `!${slidesRoot}**/node_modules/**`, // ignore node_modules
     ], gulp.series('reload'))
 
     gulp.watch(['js/**'], gulp.series('js', 'reload', 'eslint'))