diff --git a/packages/docusaurus-preset-classic/src/index.js b/packages/docusaurus-preset-classic/src/index.js
index a814214c6da1..d2dd08f8394c 100644
--- a/packages/docusaurus-preset-classic/src/index.js
+++ b/packages/docusaurus-preset-classic/src/index.js
@@ -19,8 +19,7 @@ const addAdmonitions = pluginOptions => {
 
   const admonitionsOptions = {
     remarkPlugins: (pluginOptions.remarkPlugins || []).concat([
-      admonitions,
-      pluginOptions.admonitions || {},
+      [admonitions, pluginOptions.admonitions || {}],
     ]),
   };