diff --git a/build/npm/vnu-jar.js b/build/npm/vnu-jar.js
index 8fa74ced5..e4a2c3cd9 100644
--- a/build/npm/vnu-jar.js
+++ b/build/npm/vnu-jar.js
@@ -35,7 +35,7 @@ childProcess.exec('java -version', (error, stdout, stderr) => {
     '--skip-non-html',
     // Ignore the language code warnings
     '--no-langdetect',
-    // '--Werror',
+    '--Werror',
     `--filterpattern "${ignores}"`,
     './*.html',
     'docs_html/',