diff --git a/domain/base.go b/domain/base.go
index 5cfade5b..7d1c2958 100644
--- a/domain/base.go
+++ b/domain/base.go
@@ -8,7 +8,7 @@ type BaseRepository interface {
 }
 
 var (
-	ErrNotFound = errors.New("Data not found")
+	ErrNotFound = errors.New("data not found")
 )
 
 type QueryOptions struct {
diff --git a/engine/browser.go b/engine/browser.go
index 7a39d725..fb22faa8 100644
--- a/engine/browser.go
+++ b/engine/browser.go
@@ -42,7 +42,7 @@ func (b *browser) Indexes(ifModifiedSince time.Time) (domain.ArtistIndexes, time
 	lastModified := utils.ToTime(ms)
 
 	if err != nil {
-		return nil, time.Time{}, errors.New(fmt.Sprintf("Error retrieving LastScan property: %v", err))
+		return nil, time.Time{}, errors.New(fmt.Sprintf("error retrieving LastScan property: %v", err))
 	}
 
 	if lastModified.After(ifModifiedSince) {
diff --git a/engine/common.go b/engine/common.go
index dc27ff7b..36773605 100644
--- a/engine/common.go
+++ b/engine/common.go
@@ -42,7 +42,7 @@ type Entry struct {
 type Entries []Entry
 
 var (
-	ErrDataNotFound = errors.New("Data Not Found")
+	ErrDataNotFound = errors.New("data not found")
 )
 
 func FromAlbum(al *domain.Album) Entry {
diff --git a/persistence/album_repository.go b/persistence/album_repository.go
index 60ae4fba..d9b2c07e 100644
--- a/persistence/album_repository.go
+++ b/persistence/album_repository.go
@@ -19,7 +19,7 @@ func NewAlbumRepository() domain.AlbumRepository {
 
 func (r *albumRepository) Put(m *domain.Album) error {
 	if m.Id == "" {
-		return errors.New("Album Id is not set")
+		return errors.New("album Id is not set")
 	}
 	return r.saveOrUpdate(m.Id, m)
 }
diff --git a/persistence/artist_repository.go b/persistence/artist_repository.go
index 5f39775f..c8a0e35c 100644
--- a/persistence/artist_repository.go
+++ b/persistence/artist_repository.go
@@ -18,7 +18,7 @@ func NewArtistRepository() domain.ArtistRepository {
 
 func (r *artistRepository) Put(m *domain.Artist) error {
 	if m.Id == "" {
-		return errors.New("Artist Id is not set")
+		return errors.New("artist Id is not set")
 	}
 	return r.saveOrUpdate(m.Id, m)
 }
diff --git a/persistence/index_repository.go b/persistence/index_repository.go
index 02742df6..c2147755 100644
--- a/persistence/index_repository.go
+++ b/persistence/index_repository.go
@@ -19,7 +19,7 @@ func NewArtistIndexRepository() domain.ArtistIndexRepository {
 
 func (r *artistIndexRepository) Put(m *domain.ArtistIndex) error {
 	if m.Id == "" {
-		return errors.New("Index Id is not set")
+		return errors.New("index Id is not set")
 	}
 	sort.Sort(m.Artists)
 	return r.saveOrUpdate(m.Id, m)
diff --git a/persistence/mediafile_repository.go b/persistence/mediafile_repository.go
index 966f46d6..f56ae8cb 100644
--- a/persistence/mediafile_repository.go
+++ b/persistence/mediafile_repository.go
@@ -19,7 +19,7 @@ func NewMediaFileRepository() domain.MediaFileRepository {
 
 func (r *mediaFileRepository) Put(m *domain.MediaFile) error {
 	if m.Id == "" {
-		return errors.New("MediaFile Id is not set")
+		return errors.New("mediaFile Id is not set")
 	}
 	return r.saveOrUpdate(m.Id, m)
 }
diff --git a/persistence/playlist_repository.go b/persistence/playlist_repository.go
index 730460ac..21760cc5 100644
--- a/persistence/playlist_repository.go
+++ b/persistence/playlist_repository.go
@@ -18,7 +18,7 @@ func NewPlaylistRepository() domain.PlaylistRepository {
 
 func (r *playlistRepository) Put(m *domain.Playlist) error {
 	if m.Id == "" {
-		return errors.New("Playlist Id is not set")
+		return errors.New("playlist Id is not set")
 	}
 	return r.saveOrUpdate(m.Id, m)
 }