diff --git a/src/connection.js b/src/connection.js
index 56735fe1..9adfaf96 100644
--- a/src/connection.js
+++ b/src/connection.js
@@ -526,10 +526,10 @@ class Connection {
      * without putting user credentials into the page.
      *
      * @param {string|Function} jid - The full JID that is bound by the session.
-     * @param {string} sid - The SID of the BOSH session.
-     * @param {number} rid - The current RID of the BOSH session.  This RID
+     * @param {string} [sid] - The SID of the BOSH session.
+     * @param {number} [rid] - The current RID of the BOSH session.  This RID
      *     will be used by the next request.
-     * @param {Function} callback The connect callback function.
+     * @param {Function} [callback] - The connect callback function.
      * @param {number} [wait] - The optional HTTPBIND wait value.  This is the
      *     time the server will wait before returning an empty result for
      *     a request.  The default setting of 60 seconds is recommended.
diff --git a/src/types/connection.d.ts b/src/types/connection.d.ts
index 5cd78110..59c911f4 100644
--- a/src/types/connection.d.ts
+++ b/src/types/connection.d.ts
@@ -675,10 +675,10 @@ declare class Connection {
      * without putting user credentials into the page.
      *
      * @param {string|Function} jid - The full JID that is bound by the session.
-     * @param {string} sid - The SID of the BOSH session.
-     * @param {number} rid - The current RID of the BOSH session.  This RID
+     * @param {string} [sid] - The SID of the BOSH session.
+     * @param {number} [rid] - The current RID of the BOSH session.  This RID
      *     will be used by the next request.
-     * @param {Function} callback The connect callback function.
+     * @param {Function} [callback] - The connect callback function.
      * @param {number} [wait] - The optional HTTPBIND wait value.  This is the
      *     time the server will wait before returning an empty result for
      *     a request.  The default setting of 60 seconds is recommended.
@@ -689,7 +689,7 @@ declare class Connection {
      * @param {number} [wind] - The optional HTTBIND window value.  This is the
      *     allowed range of request ids that are valid.  The default is 5.
      */
-    attach(jid: string | Function, sid: string, rid: number, callback: Function, wait?: number, hold?: number, wind?: number): void;
+    attach(jid: string | Function, sid?: string, rid?: number, callback?: Function, wait?: number, hold?: number, wind?: number): void;
     /**
      * Attempt to restore a cached BOSH session.
      *