diff --git a/Source/MQTTnet/Client/MqttClient.cs b/Source/MQTTnet/Client/MqttClient.cs
index 8556484e2..02d551f41 100644
--- a/Source/MQTTnet/Client/MqttClient.cs
+++ b/Source/MQTTnet/Client/MqttClient.cs
@@ -140,6 +140,7 @@ public async Task<MqttClientConnectResult> ConnectAsync(MqttClientOptions option
                 if (connectResult.ResultCode != MqttClientConnectResultCode.Success)
                 {
                     _logger.Warning("Connecting failed: {0}", connectResult.ResultCode);
+                    await DisconnectInternal(null, null, connectResult).ConfigureAwait(false);
                     return connectResult;
                 }