diff --git a/src/Client.js b/src/Client.js
index 2b7aaec..53d9a5f 100644
--- a/src/Client.js
+++ b/src/Client.js
@@ -549,6 +549,7 @@ class Client extends EventEmitter {
 
     /**
      * Returns the contact ID's profile picture URL, if privacy settings allow it
+     * @param {string} contactId the whatsapp user's ID
      * @returns {Promise<string>}
      */
     async getProfilePicUrl(contactId) {