diff --git a/include/sora/sora_signaling.h b/include/sora/sora_signaling.h
index 491bcb54..ecc61169 100644
--- a/include/sora/sora_signaling.h
+++ b/include/sora/sora_signaling.h
@@ -48,7 +48,7 @@ class SoraSignalingObserver {
   virtual void OnNotify(std::string text) = 0;
   virtual void OnPush(std::string text) = 0;
   virtual void OnMessage(std::string label, std::string data) = 0;
-  virtual void OnSwitched(std::string text){};
+  virtual void OnSwitched(std::string text) {}
 
   virtual void OnTrack(
       rtc::scoped_refptr<webrtc::RtpTransceiverInterface> transceiver) = 0;