diff --git a/app/assets/javascripts/discourse/app/lib/plugin-api.js b/app/assets/javascripts/discourse/app/lib/plugin-api.js
index 9635da273a7..3fa4fcf1974 100644
--- a/app/assets/javascripts/discourse/app/lib/plugin-api.js
+++ b/app/assets/javascripts/discourse/app/lib/plugin-api.js
@@ -1223,11 +1223,14 @@ class PluginApi {
   /**
    * Registers a "beforeSave" function on the composer. This allows you to
    * implement custom logic that will happen before the user makes a post.
+   * The passed function is expected to return a promise.
    *
    * Example:
    *
    * api.composerBeforeSave(() => {
-   *   console.log("Before saving, do something!");
+   *   return new Promise(() => {
+   *     console.log("Before saving, do something!")
+   *   })
    * })
    */
   composerBeforeSave(method) {