diff --git a/internal/csv/helper.go b/internal/csv/helper.go
index 2036b47..8c28a83 100644
--- a/internal/csv/helper.go
+++ b/internal/csv/helper.go
@@ -1,6 +1,7 @@
 package csv
 
 import (
+	"context"
 	"encoding/csv"
 	"os"
 
@@ -9,7 +10,6 @@ import (
 )
 
 type Helper struct {
-	fx.In
 	csvFile   *os.File
 	csvWriter *csv.Writer
 	logger    *zap.Logger
@@ -23,11 +23,19 @@ func NewHelper(lc fx.Lifecycle, logger *zap.Logger) *Helper {
 
 	csvWriter := csv.NewWriter(csvFile)
 
-	return &Helper{
+	helper := &Helper{
 		csvFile:   csvFile,
 		csvWriter: csvWriter,
 		logger:    logger,
 	}
+
+	lc.Append(fx.Hook{
+		OnStop: func(context.Context) error {
+			return helper.Close()
+		},
+	})
+
+	return helper
 }
 
 func (h *Helper) AddEntry(date string, topic string, message string) error {
diff --git a/internal/mqtt/mqtt.go b/internal/mqtt/mqtt.go
index eb3994e..2a15055 100644
--- a/internal/mqtt/mqtt.go
+++ b/internal/mqtt/mqtt.go
@@ -35,6 +35,11 @@ func NewClient(logger *zap.Logger, config *config.Config, csvHelper *csv.Helper)
 		}
 	})
 
+	if config.Username != "" && config.Password != "" {
+		opts.SetUsername(config.Username)
+		opts.SetPassword(config.Password)
+	}
+
 	c := mqtt.NewClient(opts)
 	if token := c.Connect(); token.Wait() && token.Error() != nil {
 		logger.Fatal("error connecting to MQTT broker", zap.Error(token.Error()))