diff --git a/src/TransportNode.js b/src/TransportNode.js
index db09830..83ee5ae 100644
--- a/src/TransportNode.js
+++ b/src/TransportNode.js
@@ -12,23 +12,24 @@ export class TransportNode extends AudioWorkletNode {
 
   /** @type {(this: MessagePort, ev: MessageEvent<any>) => any} */
   handleMessage = (message) => {
-    if (message.data && message.data.type === "elapsed") {
-      this.app.clock.elapsed = message.data.value
-    }
-    if (message.data && message.data.type === "bang") {
-      if (this.app.settings.send_clock)
-        this.app.api.MidiConnection.sendMidiClock();
-      this.app.clock.tick++;
-      const futureTimeStamp = this.app.clock.convertTicksToTimeposition(
-        this.app.clock.tick
-      );
-      this.app.clock.time_position = futureTimeStamp;
-      this.timeviewer.innerHTML = `${zeroPad(futureTimeStamp.bar, 2)}:${futureTimeStamp.beat + 1
-        }:${zeroPad(futureTimeStamp.pulse, 2)} / ${this.app.clock.bpm}`;
-      if (this.app.exampleIsPlaying) {
-        tryEvaluate(this.app, this.app.example_buffer);
-      } else {
-        tryEvaluate(this.app, this.app.global_buffer);
+    if(message.data) {
+      if (message.data.type === "elapsed") {
+        this.app.clock.elapsed = message.data.value
+      } else if (message.data.type === "bang") {
+        if (this.app.settings.send_clock)
+          this.app.api.MidiConnection.sendMidiClock();
+        this.app.clock.tick++;
+        const futureTimeStamp = this.app.clock.convertTicksToTimeposition(
+          this.app.clock.tick
+        );
+        this.app.clock.time_position = futureTimeStamp;
+        this.timeviewer.innerHTML = `${zeroPad(futureTimeStamp.bar, 2)}:${futureTimeStamp.beat + 1
+          }:${zeroPad(futureTimeStamp.pulse, 2)} / ${this.app.clock.bpm}`;
+        if (this.app.exampleIsPlaying) {
+          tryEvaluate(this.app, this.app.example_buffer);
+        } else {
+          tryEvaluate(this.app, this.app.global_buffer);
+        }
       }
     }
   };