diff --git a/core/agents/lastfm/client.go b/core/agents/lastfm/client.go
index cdb297997..2757c96f8 100644
--- a/core/agents/lastfm/client.go
+++ b/core/agents/lastfm/client.go
@@ -14,7 +14,7 @@ import (
 	"time"
 
 	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/utils"
+	"golang.org/x/exp/slices"
 )
 
 const (
@@ -204,7 +204,7 @@ func (c *Client) sign(params url.Values) {
 	// the parameters must be in order before hashing
 	keys := make([]string, 0, len(params))
 	for k := range params {
-		if utils.StringInSlice(k, []string{"format", "callback"}) {
+		if slices.Contains([]string{"format", "callback"}, k) {
 			continue
 		}
 		keys = append(keys, k)
diff --git a/utils/files.go b/model/file_types.go
similarity index 55%
rename from utils/files.go
rename to model/file_types.go
index 5e9150c94..78dd7eaff 100644
--- a/utils/files.go
+++ b/model/file_types.go
@@ -1,9 +1,11 @@
-package utils
+package model
 
 import (
 	"mime"
 	"path/filepath"
 	"strings"
+
+	"golang.org/x/exp/slices"
 )
 
 var excludeAudioType = []string{
@@ -14,10 +16,15 @@ var excludeAudioType = []string{
 func IsAudioFile(filePath string) bool {
 	extension := filepath.Ext(filePath)
 	mimeType := mime.TypeByExtension(extension)
-	return !StringInSlice(mimeType, excludeAudioType) && strings.HasPrefix(mimeType, "audio/")
+	return !slices.Contains(excludeAudioType, mimeType) && strings.HasPrefix(mimeType, "audio/")
 }
 
 func IsImageFile(filePath string) bool {
 	extension := filepath.Ext(filePath)
 	return strings.HasPrefix(mime.TypeByExtension(extension), "image/")
 }
+
+func IsValidPlaylist(filePath string) bool {
+	extension := strings.ToLower(filepath.Ext(filePath))
+	return extension == ".m3u" || extension == ".m3u8" || extension == ".nsp"
+}
diff --git a/model/file_types_test.go b/model/file_types_test.go
new file mode 100644
index 000000000..93301e151
--- /dev/null
+++ b/model/file_types_test.go
@@ -0,0 +1,61 @@
+package model_test
+
+import (
+	"path/filepath"
+
+	"github.com/navidrome/navidrome/model"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("File Types()", func() {
+	Describe("IsAudioFile", func() {
+		It("returns true for a MP3 file", func() {
+			Expect(model.IsAudioFile(filepath.Join("path", "to", "test.mp3"))).To(BeTrue())
+		})
+
+		It("returns true for a FLAC file", func() {
+			Expect(model.IsAudioFile("test.flac")).To(BeTrue())
+		})
+
+		It("returns false for a non-audio file", func() {
+			Expect(model.IsAudioFile("test.jpg")).To(BeFalse())
+		})
+
+		It("returns false for m3u files", func() {
+			Expect(model.IsAudioFile("test.m3u")).To(BeFalse())
+		})
+
+		It("returns false for pls files", func() {
+			Expect(model.IsAudioFile("test.pls")).To(BeFalse())
+		})
+	})
+
+	Describe("IsImageFile()", func() {
+		It("returns true for a PNG file", func() {
+			Expect(model.IsImageFile(filepath.Join("path", "to", "test.png"))).To(BeTrue())
+		})
+
+		It("returns true for a JPEG file", func() {
+			Expect(model.IsImageFile("test.JPEG")).To(BeTrue())
+		})
+
+		It("returns false for a non-image file", func() {
+			Expect(model.IsImageFile("test.mp3")).To(BeFalse())
+		})
+	})
+
+	Describe("IsValidPlaylist()", func() {
+		It("returns true for a M3U file", func() {
+			Expect(model.IsValidPlaylist(filepath.Join("path", "to", "test.m3u"))).To(BeTrue())
+		})
+
+		It("returns true for a M3U8 file", func() {
+			Expect(model.IsValidPlaylist(filepath.Join("path", "to", "test.m3u8"))).To(BeTrue())
+		})
+
+		It("returns false for a non-playlist file", func() {
+			Expect(model.IsValidPlaylist("testm3u")).To(BeFalse())
+		})
+	})
+})
diff --git a/model/playlist.go b/model/playlist.go
index cef45c473..06329cf29 100644
--- a/model/playlist.go
+++ b/model/playlist.go
@@ -2,7 +2,6 @@ package model
 
 import (
 	"fmt"
-	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
@@ -138,8 +137,3 @@ type PlaylistTrackRepository interface {
 	DeleteAll() error
 	Reorder(pos int, newPos int) error
 }
-
-func IsValidPlaylist(filePath string) bool {
-	extension := strings.ToLower(filepath.Ext(filePath))
-	return extension == ".m3u" || extension == ".m3u8" || extension == ".nsp"
-}
diff --git a/model/playlists_test.go b/model/playlists_test.go
index b5e2deb95..600e116cc 100644
--- a/model/playlists_test.go
+++ b/model/playlists_test.go
@@ -1,27 +1,11 @@
 package model_test
 
 import (
-	"path/filepath"
-
 	"github.com/navidrome/navidrome/model"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
 
-var _ = Describe("IsValidPlaylist()", func() {
-	It("returns true for a M3U file", func() {
-		Expect(model.IsValidPlaylist(filepath.Join("path", "to", "test.m3u"))).To(BeTrue())
-	})
-
-	It("returns true for a M3U8 file", func() {
-		Expect(model.IsValidPlaylist(filepath.Join("path", "to", "test.m3u8"))).To(BeTrue())
-	})
-
-	It("returns false for a non-playlist file", func() {
-		Expect(model.IsValidPlaylist("testm3u")).To(BeFalse())
-	})
-})
-
 var _ = Describe("Playlist", func() {
 	Describe("ToM3U8()", func() {
 		var pls model.Playlist
diff --git a/scanner/tag_scanner.go b/scanner/tag_scanner.go
index 9cfe0e32f..37168b2cc 100644
--- a/scanner/tag_scanner.go
+++ b/scanner/tag_scanner.go
@@ -402,7 +402,7 @@ func loadAllAudioFiles(dirPath string) (map[string]fs.DirEntry, error) {
 			continue
 		}
 		filePath := filepath.Join(dirPath, f.Name())
-		if !utils.IsAudioFile(filePath) {
+		if !model.IsAudioFile(filePath) {
 			continue
 		}
 		fileInfos[filePath] = f
diff --git a/scanner/walk_dir_tree.go b/scanner/walk_dir_tree.go
index b32ba11f3..3f8d10f4d 100644
--- a/scanner/walk_dir_tree.go
+++ b/scanner/walk_dir_tree.go
@@ -95,11 +95,11 @@ func loadDir(ctx context.Context, dirPath string) ([]string, *dirStats, error) {
 				stats.ModTime = fileInfo.ModTime()
 			}
 			switch {
-			case utils.IsAudioFile(entry.Name()):
+			case model.IsAudioFile(entry.Name()):
 				stats.AudioFilesCount++
 			case model.IsValidPlaylist(entry.Name()):
 				stats.HasPlaylist = true
-			case utils.IsImageFile(entry.Name()):
+			case model.IsImageFile(entry.Name()):
 				stats.Images = append(stats.Images, entry.Name())
 				if fileInfo.ModTime().After(stats.ImagesUpdatedAt) {
 					stats.ImagesUpdatedAt = fileInfo.ModTime()
diff --git a/utils/files_test.go b/utils/files_test.go
deleted file mode 100644
index 917960c8c..000000000
--- a/utils/files_test.go
+++ /dev/null
@@ -1,46 +0,0 @@
-package utils
-
-import (
-	"path/filepath"
-
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-)
-
-var _ = Describe("Files", func() {
-	Describe("IsAudioFile", func() {
-		It("returns true for a MP3 file", func() {
-			Expect(IsAudioFile(filepath.Join("path", "to", "test.mp3"))).To(BeTrue())
-		})
-
-		It("returns true for a FLAC file", func() {
-			Expect(IsAudioFile("test.flac")).To(BeTrue())
-		})
-
-		It("returns false for a non-audio file", func() {
-			Expect(IsAudioFile("test.jpg")).To(BeFalse())
-		})
-
-		It("returns false for m3u files", func() {
-			Expect(IsAudioFile("test.m3u")).To(BeFalse())
-		})
-
-		It("returns false for pls files", func() {
-			Expect(IsAudioFile("test.pls")).To(BeFalse())
-		})
-	})
-
-	Describe("IsImageFile", func() {
-		It("returns true for a PNG file", func() {
-			Expect(IsImageFile(filepath.Join("path", "to", "test.png"))).To(BeTrue())
-		})
-
-		It("returns true for a JPEG file", func() {
-			Expect(IsImageFile("test.JPEG")).To(BeTrue())
-		})
-
-		It("returns false for a non-image file", func() {
-			Expect(IsImageFile("test.mp3")).To(BeFalse())
-		})
-	})
-})
diff --git a/utils/strings.go b/utils/strings.go
index 45bb39b16..c88c96b3e 100644
--- a/utils/strings.go
+++ b/utils/strings.go
@@ -17,15 +17,6 @@ func NoArticle(name string) string {
 	return name
 }
 
-func StringInSlice(a string, slice []string) bool {
-	for _, b := range slice {
-		if b == a {
-			return true
-		}
-	}
-	return false
-}
-
 func InsertString(slice []string, value string, index int) []string {
 	return append(slice[:index], append([]string{value}, slice[index:]...)...)
 }
diff --git a/utils/strings_test.go b/utils/strings_test.go
index 20a59e166..165990754 100644
--- a/utils/strings_test.go
+++ b/utils/strings_test.go
@@ -35,20 +35,6 @@ var _ = Describe("Strings", func() {
 		})
 	})
 
-	Describe("StringInSlice", func() {
-		It("returns false if slice is empty", func() {
-			Expect(StringInSlice("test", nil)).To(BeFalse())
-		})
-
-		It("returns false if string is not found in slice", func() {
-			Expect(StringInSlice("aaa", []string{"bbb", "ccc"})).To(BeFalse())
-		})
-
-		It("returns true if string is found in slice", func() {
-			Expect(StringInSlice("bbb", []string{"bbb", "aaa", "ccc"})).To(BeTrue())
-		})
-	})
-
 	Describe("MoveString", func() {
 		It("moves item to end of slice", func() {
 			Expect(MoveString([]string{"1", "2", "3"}, 0, 2)).To(ConsistOf("2", "3", "1"))