diff --git a/index.html b/index.html
index a9b0eed..0273fdb 100644
--- a/index.html
+++ b/index.html
@@ -142,18 +142,21 @@
             async askForSerialPort() {
                 this.connection = await SerialConnection.open();
                 this.connection.on("connected", () => this.onConnected());
+                this.connection.on("disconnected", () => this.onDisconnected());
                 // this.connection.on("tx", (data) => console.log("tx", data));
                 // this.connection.on("rx", (data) => console.log("rx", data));
             },
             async askForBleDevice() {
                 this.connection = await BleConnection.open();
                 this.connection.on("connected", () => this.onConnected());
+                this.connection.on("disconnected", () => this.onDisconnected());
                 // this.connection.on("tx", (data) => console.log("tx", data));
                 // this.connection.on("rx", (data) => console.log("rx", data));
             },
             async disconnect() {
                 if(this.connection){
                     await this.connection.close();
+                    this.onDisconnected();
                     this.connection = null;
                 }
             },
@@ -166,6 +169,10 @@
                     await this.loadContacts();
                 });
             },
+            onDisconnected() {
+                console.log("disconnected");
+                this.connection = null;
+            },
             async loadSelfInfo() {
                 this.selfInfo = await this.connection.getSelfInfo();
             },
diff --git a/src/connection/serial_connection.js b/src/connection/serial_connection.js
index 3e90d92..c941875 100644
--- a/src/connection/serial_connection.js
+++ b/src/connection/serial_connection.js
@@ -15,6 +15,11 @@ class SerialConnection extends Connection {
         this.readBuffer = [];
         this.readLoop();
 
+        // listen for disconnect
+        this.serialPort.addEventListener("disconnect", () => {
+            this.emit("disconnected");
+        });
+
         // fire connected callback after constructor has returned
         setTimeout(() => {
             this.onConnected();