diff --git a/src/pattern.js b/src/pattern.js
index 96d51b6eaaa..c4bb02d9665 100644
--- a/src/pattern.js
+++ b/src/pattern.js
@@ -223,7 +223,10 @@ Pattern.prototype.loadPluginHooks = function(plugin) {
   for (let hook of this.hooks.all) {
     if (typeof plugin.hooks[hook] === "function") {
       this.on(hook, plugin.hooks[hook]);
-    } else if (typeof plugin.hooks[hook] === "array") {
+    } else if (
+      typeof plugin.hooks[hook] !== "undefined" &&
+      plugin.hooks[hook].isArray()
+    ) {
       for (let method of plugin.hooks[hook]) {
         this.on(hook, method);
       }