diff --git a/lib/transports/ws2.js b/lib/transports/ws2.js
index bdcfb881..2d2f301e 100644
--- a/lib/transports/ws2.js
+++ b/lib/transports/ws2.js
@@ -1427,9 +1427,23 @@ class WSv2 extends EventEmitter {
    * @private
    */
   _sendCalc (msg) {
-    debug('req calc: %j', msg)
+    debug('req calc (throttled): %j', msg)
+    this.send(msg)  // use send to check if we are still connected
+  }
 
-    this._ws.send(JSON.stringify(msg))
+  /**
+   * send a ping (to receive a pong)
+   * https://docs.bitfinex.com/v2/docs/ws-general#section-ping-pong
+   *
+   * @param {number} cid
+   */
+  ping (cid) {
+    const ping = {
+      'event': 'ping',
+      'cid': cid
+    }
+
+    this.send(ping) // use send to check if we are still connected
   }
 
   /**
diff --git a/test/lib/transports/ws2-unit.js b/test/lib/transports/ws2-unit.js
index 13ae96c5..dc2acb29 100644
--- a/test/lib/transports/ws2-unit.js
+++ b/test/lib/transports/ws2-unit.js
@@ -58,15 +58,21 @@ describe('WSv2 utilities', () => {
   })
 
   it('_sendCalc: stringifes payload & passes it to the ws client', (done) => {
-    const ws = new WSv2()
+    const wss = new MockWSv2Server()
+    const ws = createTestWSv2Instance()
 
-    ws._ws = {}
-    ws._ws.send = (data) => {
-      assert.equal(data, '[]')
-      done()
-    }
+    ws.on('open', () => {
 
-    ws._sendCalc([])
+      ws._ws.send = (data) => {
+        wss.close()
+        assert.equal(data, '[]')
+        done()
+      }
+
+      ws._sendCalc([])
+    })
+
+    ws.open()
   })
 
   it('notifyUI: throws error if supplied invalid arguments', () => {