diff --git a/lib/index.js b/lib/index.js
index f6af342..f0b4dc8 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -101,23 +101,23 @@ function initNet(peer, config) {
 
   /**
    * @param {Address} address
-   * @param {CB<RPC>} cb
+   * @param {CB<RPC>=} cb
    */
   function connect(address, cb) {
     connections.connect(address).then(
-      (result) => cb(null, result),
-      (err) => cb(err)
+      (result) => cb?.(null, result),
+      (err) => cb?.(err)
     )
   }
 
   /**
    * @param {Address} address
-   * @param {CB<boolean>} cb
+   * @param {CB<boolean>=} cb
    */
   function disconnect(address, cb) {
     return connections.disconnect(address).then(
-      (result) => cb(null, result),
-      (err) => cb(err)
+      (result) => cb?.(null, result),
+      (err) => cb?.(err)
     )
   }