diff --git a/packages/@vuepress/core/lib/node/plugin-api/util.js b/packages/@vuepress/core/lib/node/plugin-api/util.js
index af2ede4440..a0d7be90ed 100644
--- a/packages/@vuepress/core/lib/node/plugin-api/util.js
+++ b/packages/@vuepress/core/lib/node/plugin-api/util.js
@@ -22,7 +22,7 @@ exports.flattenPlugin = function (
   pluginContext,
   self
 ) {
-  const { valid, warnMsg } = assertTypes(pluginOptions, [Object, Boolean])
+  const { valid, warnMsg } = assertTypes(pluginOptions, [Object, Array, Boolean])
   if (!valid) {
     if (pluginOptions !== undefined) {
       logger.warn(