diff --git a/routes/heartbeat.go b/routes/heartbeat.go
index d1acd9f..02c3f57 100644
--- a/routes/heartbeat.go
+++ b/routes/heartbeat.go
@@ -21,7 +21,7 @@ func (h *HeartbeatHandler) Post(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	var heartbeats []models.Heartbeat
+	var heartbeats []*models.Heartbeat
 	user := r.Context().Value(models.UserKey).(*models.User)
 	opSys, editor, _ := utils.ParseUserAgent(r.Header.Get("User-Agent"))
 
@@ -32,8 +32,7 @@ func (h *HeartbeatHandler) Post(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	for i := 0; i < len(heartbeats); i++ {
-		h := &heartbeats[i]
+	for _, h := range heartbeats {
 		h.OperatingSystem = opSys
 		h.Editor = editor
 		h.User = user
@@ -46,7 +45,7 @@ func (h *HeartbeatHandler) Post(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	if err := h.HeartbeatSrvc.InsertBatch(&heartbeats); err != nil {
+	if err := h.HeartbeatSrvc.InsertBatch(heartbeats); err != nil {
 		w.WriteHeader(500)
 		os.Stderr.WriteString(err.Error())
 		return
diff --git a/services/aggregation.go b/services/aggregation.go
index c62bd2f..2ff12e3 100644
--- a/services/aggregation.go
+++ b/services/aggregation.go
@@ -84,13 +84,10 @@ func (srv *AggregationService) aggregate(from, to time.Time, user *models.User)
 	return aggregations
 }
 
-func (srv *AggregationService) aggregateBy(heartbeats *[]models.Heartbeat, aggregationType uint8) []models.AggregationItem {
-	beats := *heartbeats
+func (srv *AggregationService) aggregateBy(heartbeats []*models.Heartbeat, aggregationType uint8) []models.AggregationItem {
 	durations := make(map[string]time.Duration)
 
-	for i := 0; i < len(beats); i++ {
-		h := &beats[i]
-
+	for i, h := range heartbeats {
 		var key string
 		switch aggregationType {
 		case models.AggregationProject:
@@ -111,7 +108,7 @@ func (srv *AggregationService) aggregateBy(heartbeats *[]models.Heartbeat, aggre
 			continue
 		}
 
-		timePassed := h.Time.Time().Sub((&beats[i-1]).Time.Time())
+		timePassed := h.Time.Time().Sub(heartbeats[i-1].Time.Time())
 		timeThresholded := math.Min(float64(timePassed), float64(time.Duration(2)*time.Minute))
 		durations[key] += time.Duration(int64(timeThresholded))
 	}
diff --git a/services/heartbeat.go b/services/heartbeat.go
index 901b67d..5f947df 100644
--- a/services/heartbeat.go
+++ b/services/heartbeat.go
@@ -15,9 +15,9 @@ type HeartbeatService struct {
 	Db     *gorm.DB
 }
 
-func (srv *HeartbeatService) InsertBatch(heartbeats *[]models.Heartbeat) error {
+func (srv *HeartbeatService) InsertBatch(heartbeats []*models.Heartbeat) error {
 	var batch []interface{}
-	for _, h := range *heartbeats {
+	for _, h := range heartbeats {
 		batch = append(batch, h)
 	}
 
@@ -27,13 +27,13 @@ func (srv *HeartbeatService) InsertBatch(heartbeats *[]models.Heartbeat) error {
 	return nil
 }
 
-func (srv *HeartbeatService) GetAllFrom(date time.Time, user *models.User) (*[]models.Heartbeat, error) {
-	var heartbeats []models.Heartbeat
+func (srv *HeartbeatService) GetAllFrom(date time.Time, user *models.User) ([]*models.Heartbeat, error) {
+	var heartbeats []*models.Heartbeat
 	if err := srv.Db.
 		Where(&models.Heartbeat{UserID: user.ID}).
 		Where("time > ?", date).
-		Find(&heartbeats).Error; err != nil {
+		Find(heartbeats).Error; err != nil {
 		return nil, err
 	}
-	return &heartbeats, nil
+	return heartbeats, nil
 }