diff --git a/node/src/client.js b/node/src/client.js
index d7da8f4..af913f4 100644
--- a/node/src/client.js
+++ b/node/src/client.js
@@ -422,7 +422,7 @@ export default class PeerClient {
 		this.stopped = false
 		this.notificationID = 0
 		this.maxCommandID = 0
-		this.peerID = null
+		this.peerID = ""
 		this.deviceName = "KakaoTalk Bridge"
 		/** @type {[string]} */
 		this.loggingKeys = []
@@ -483,11 +483,11 @@ export default class PeerClient {
 		if (this.peerID && this.manager.clients.get(this.peerID) === this) {
 			this.manager.clients.delete(this.peerID)
 		}
-		this.log(`Connection closed (peer: ${this.peerID})`)
+		this.log(`Connection closed (peer: ${this.peerID || "unknown peer"})`)
 	}
 
 	#closeUsers() {
-		this.log("Closing all API clients for", this.peerID)
+		this.log(`Closing all API clients for ${this.peerID || "unknown peer"}`)
 		for (const userClient of this.userClients.values()) {
 			userClient.disconnect()
 		}