diff --git a/config/legacy.go b/config/legacy.go
index 80ad686..ff3e7f2 100644
--- a/config/legacy.go
+++ b/config/legacy.go
@@ -76,8 +76,6 @@ func migrateLegacyConfig() error {
 		basePath = basePathEnv
 	}
 
-	cleanUp := cfg.Section("app").Key("cleanup").MustBool(false)
-
 	// Read custom languages
 	customLangs := make(map[string]string)
 	languageKeys := cfg.Section("languages").Keys()
@@ -89,7 +87,6 @@ func migrateLegacyConfig() error {
 	config := &Config{
 		Env: env,
 		App: appConfig{
-			CleanUp:         cleanUp,
 			CustomLanguages: customLangs,
 		},
 		Security: securityConfig{
diff --git a/main.go b/main.go
index 99c15ca..0538b49 100644
--- a/main.go
+++ b/main.go
@@ -56,11 +56,6 @@ func main() {
 		log.SetFlags(log.LstdFlags | log.Lshortfile)
 	}
 
-	// Show data loss warning
-	if config.App.CleanUp {
-		promptAbort("`CLEANUP` is set to `true`, which may cause data loss. Are you sure to continue?", 5)
-	}
-
 	// Connect to database
 	var err error
 	db, err = gorm.Open(config.Db.GetDialector(), &gorm.Config{})
@@ -102,10 +97,6 @@ func main() {
 	// Aggregate heartbeats to summaries and persist them
 	go aggregationService.Schedule()
 
-	if config.App.CleanUp {
-		go heartbeatService.ScheduleCleanUp()
-	}
-
 	// TODO: move endpoint registration to the respective routes files
 
 	// Handlers
@@ -194,11 +185,3 @@ func runDatabaseMigrations() {
 		log.Fatal(err)
 	}
 }
-
-func promptAbort(message string, timeoutSec int) {
-	log.Printf("[WARNING] %s.\nTo abort server startup, press Ctrl+C.\n", message)
-	for i := timeoutSec; i > 0; i-- {
-		log.Printf("Starting in %d seconds ...\n", i)
-		time.Sleep(1 * time.Second)
-	}
-}
diff --git a/models/language_mapping.go b/models/language_mapping.go
index 13b05b8..e0aee9d 100644
--- a/models/language_mapping.go
+++ b/models/language_mapping.go
@@ -4,14 +4,18 @@ type LanguageMapping struct {
 	ID        uint   `json:"id" gorm:"primary_key"`
 	User      *User  `json:"-" gorm:"not null"`
 	UserID    string `json:"-" gorm:"not null; index:idx_language_mapping_user; uniqueIndex:idx_language_mapping_composite"`
-	Extension string `json:"extension" gorm:"uniqueIndex:idx_language_mapping_composite"`
-	Language  string `json:"language"`
+	Extension string `json:"extension" gorm:"uniqueIndex:idx_language_mapping_composite; type:varchar(16)"`
+	Language  string `json:"language" gorm:"type:varchar(64)"`
 }
 
-func validateLanguage(language string) bool {
-	return len(language) >= 1
+func (m *LanguageMapping) IsValid() bool {
+	return m.validateLanguage() && m.validateExtension()
 }
 
-func validateExtension(extension string) bool {
-	return len(extension) >= 1
+func (m *LanguageMapping) validateLanguage() bool {
+	return len(m.Language) >= 1
+}
+
+func (m *LanguageMapping) validateExtension() bool {
+	return len(m.Extension) >= 1
 }
diff --git a/repositories/language_mapping.go b/repositories/language_mapping.go
index 27270fe..9a18fb3 100644
--- a/repositories/language_mapping.go
+++ b/repositories/language_mapping.go
@@ -1,6 +1,7 @@
 package repositories
 
 import (
+	"errors"
 	"github.com/muety/wakapi/config"
 	"github.com/muety/wakapi/models"
 	"gorm.io/gorm"
@@ -34,6 +35,9 @@ func (r *LanguageMappingRepository) GetByUser(userId string) ([]*models.Language
 }
 
 func (r *LanguageMappingRepository) Insert(mapping *models.LanguageMapping) (*models.LanguageMapping, error) {
+	if !mapping.IsValid() {
+		return nil, errors.New("invalid mapping")
+	}
 	result := r.db.Create(mapping)
 	if err := result.Error; err != nil {
 		return nil, err
diff --git a/repositories/user.go b/repositories/user.go
index 71e3423..e3964e5 100644
--- a/repositories/user.go
+++ b/repositories/user.go
@@ -54,7 +54,7 @@ func (r *UserRepository) InsertOrGet(user *models.User) (*models.User, bool, err
 }
 
 func (r *UserRepository) Update(user *models.User) (*models.User, error) {
-	result := r.db.Model(&models.User{}).Updates(user)
+	result := r.db.Model(user).Updates(user)
 	if err := result.Error; err != nil {
 		return nil, err
 	}
diff --git a/services/heartbeat.go b/services/heartbeat.go
index 48a57dd..0123a73 100644
--- a/services/heartbeat.go
+++ b/services/heartbeat.go
@@ -1,11 +1,8 @@
 package services
 
 import (
-	"github.com/jasonlvhit/gocron"
 	"github.com/muety/wakapi/config"
 	"github.com/muety/wakapi/repositories"
-	"github.com/muety/wakapi/utils"
-	"log"
 	"time"
 
 	"github.com/muety/wakapi/models"
@@ -49,23 +46,6 @@ func (srv *HeartbeatService) DeleteBefore(t time.Time) error {
 	return srv.repository.DeleteBefore(t)
 }
 
-func (srv *HeartbeatService) CleanUp() error {
-	refTime := utils.StartOfToday().Add(-cleanUpInterval)
-	if err := srv.DeleteBefore(refTime); err != nil {
-		log.Printf("Failed to clean up heartbeats older than %v – %v\n", refTime, err)
-		return err
-	}
-	log.Printf("Successfully cleaned up heartbeats older than %v\n", refTime)
-	return nil
-}
-
-func (srv *HeartbeatService) ScheduleCleanUp() {
-	srv.CleanUp()
-
-	gocron.Every(1).Day().At("02:30").Do(srv.CleanUp)
-	<-gocron.Start()
-}
-
 func (srv *HeartbeatService) augmented(heartbeats []*models.Heartbeat, userId string) ([]*models.Heartbeat, error) {
 	languageMapping, err := srv.languageMappingSrvc.ResolveByUser(userId)
 	if err != nil {