diff --git a/lib/sender.js b/lib/sender.js
index d385d6456..3ea2fc147 100644
--- a/lib/sender.js
+++ b/lib/sender.js
@@ -174,7 +174,7 @@ class Sender {
   /**
    * Frames and sends a ping message.
    *
-   * @param {*} data The message to send
+   * @param {Buffer} data The message to send
    * @param {Boolean} mask Specifies whether or not to mask `data`
    * @param {Boolean} readOnly Specifies whether `data` can be modified
    * @param {Function} cb Callback
@@ -218,7 +218,7 @@ class Sender {
   /**
    * Frames and sends a pong message.
    *
-   * @param {*} data The message to send
+   * @param {Buffer} data The message to send
    * @param {Boolean} mask Specifies whether or not to mask `data`
    * @param {Boolean} readOnly Specifies whether `data` can be modified
    * @param {Function} cb Callback