diff --git a/node_zeromq/zmq-tests.ts b/node_zeromq/zmq-tests.ts
index 6481932598..696a98c13b 100644
--- a/node_zeromq/zmq-tests.ts
+++ b/node_zeromq/zmq-tests.ts
@@ -5,6 +5,7 @@ import zmq = require('zmq');
 function test1() {
     var sock = zmq.socket('push');
     sock.bindSync('tcp://127.0.0.1:3000');
+    sock.unbindSync('tcp://127.0.0.1:3000');
     sock.send("some work");
 }
 
@@ -28,6 +29,9 @@ function test4() {
     sock.bind('tcp://127.0.0.1', err => {
         sock.send("some work");
     });
+    sock.unbind('tcp://127.0.0.1', err => {
+        //
+    });
 }
 
 function test5() {
diff --git a/node_zeromq/zmq.d.ts b/node_zeromq/zmq.d.ts
index e84615c858..8d29e05691 100644
--- a/node_zeromq/zmq.d.ts
+++ b/node_zeromq/zmq.d.ts
@@ -85,7 +85,7 @@ declare module 'zmq' {
          * @param addr Socket address
          * @param cb Bind callback
          */
-        bind(addr: string, callback: (error: string) => void ): Socket;
+        bind(addr: string, callback?: (error: string) => void ): Socket;
 
         /**
          * Sync bind.
@@ -94,6 +94,23 @@ declare module 'zmq' {
          */
         bindSync(addr: string): Socket;
 
+        /**
+         * Async unbind.
+         *
+         * Emits the "unbind" event.
+         *
+         * @param addr Socket address
+         * @param cb Unind callback
+         */
+        unbind(addr: string, callback?: (error: string) => void ): Socket;
+
+        /**
+         * Sync unbind.
+         *
+         * @param addr Socket address
+         */
+        unbindSync(addr: string): Socket;
+
         /**
          * Connect to `addr`.
          *