diff --git a/core/artwork/artwork_internal_test.go b/core/artwork/artwork_internal_test.go
index 380352d3f..0c03ef0ca 100644
--- a/core/artwork/artwork_internal_test.go
+++ b/core/artwork/artwork_internal_test.go
@@ -7,12 +7,11 @@ import (
 	"image/jpeg"
 	"image/png"
 	"io"
-
 	"os"
 	"path/filepath"
+	"time"
 
 	_ "github.com/gen2brain/webp"
-
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/conf/configtest"
 	"github.com/navidrome/navidrome/log"
@@ -146,6 +145,51 @@ var _ = Describe("Artwork", func() {
 				Entry(nil, " embedded , front.* , cover.*,folder.*", "tests/fixtures/artist/an-album/test.mp3"),
 			)
 		})
+		Context("LastUpdated", func() {
+			// Regression test for #5377: LastUpdated feeds the HTTP Last-Modified header.
+			// It must return max(album.UpdatedAt, ImagesUpdatedAt) so browsers revalidate
+			// cached cover art when only the image file changes.
+			now := time.Now().Truncate(time.Second)
+			DescribeTable("returns the max of album.UpdatedAt and ImagesUpdatedAt",
+				func(albumUpdatedAt, imagesUpdatedAt, expected time.Time) {
+					album := model.Album{ID: "al1", UpdatedAt: albumUpdatedAt}
+					folderRepo.result = []model.Folder{{ImagesUpdatedAt: imagesUpdatedAt}}
+					ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{album})
+
+					ar, err := newAlbumArtworkReader(ctx, aw, album.CoverArtID(), nil)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(ar.LastUpdated()).To(Equal(expected))
+				},
+				Entry("album newer than images", now, now.Add(-1*time.Hour), now),
+				Entry("images newer than album", now.Add(-24*time.Hour), now.Add(-1*time.Hour), now.Add(-1*time.Hour)),
+				Entry("equal timestamps", now, now, now),
+			)
+		})
+	})
+	Describe("discArtworkReader", func() {
+		Context("LastUpdated", func() {
+			// Regression test for #5377: same bug as albumArtworkReader — disc covers
+			// must also revalidate when the image file changes, not only when media files do.
+			now := time.Now().Truncate(time.Second)
+			DescribeTable("returns the max of album.UpdatedAt and ImagesUpdatedAt",
+				func(albumUpdatedAt, imagesUpdatedAt, expected time.Time) {
+					album := model.Album{ID: "al1", UpdatedAt: albumUpdatedAt}
+					folderRepo.result = []model.Folder{{ImagesUpdatedAt: imagesUpdatedAt}}
+					ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{album})
+					ds.MediaFile(ctx).(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
+						{ID: "mf1", AlbumID: "al1", DiscNumber: 1, Path: "tests/fixtures/test.mp3"},
+					})
+
+					artID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID("al1", 1), nil)
+					dr, err := newDiscArtworkReader(ctx, aw, artID)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(dr.LastUpdated()).To(Equal(expected))
+				},
+				Entry("album newer than images", now, now.Add(-1*time.Hour), now),
+				Entry("images newer than album", now.Add(-24*time.Hour), now.Add(-1*time.Hour), now.Add(-1*time.Hour)),
+				Entry("equal timestamps", now, now, now),
+			)
+		})
 	})
 	Describe("artistArtworkReader", func() {
 		Context("Multiple covers", func() {
diff --git a/core/artwork/reader_album.go b/core/artwork/reader_album.go
index 641b12b33..35d489b6c 100644
--- a/core/artwork/reader_album.go
+++ b/core/artwork/reader_album.go
@@ -72,7 +72,7 @@ func (a *albumArtworkReader) Key() string {
 	)
 }
 func (a *albumArtworkReader) LastUpdated() time.Time {
-	return a.album.UpdatedAt
+	return a.lastUpdate
 }
 
 func (a *albumArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
diff --git a/core/artwork/reader_disc.go b/core/artwork/reader_disc.go
index 5a7a8a65e..30d4968e1 100644
--- a/core/artwork/reader_disc.go
+++ b/core/artwork/reader_disc.go
@@ -116,7 +116,7 @@ func (d *discArtworkReader) Key() string {
 }
 
 func (d *discArtworkReader) LastUpdated() time.Time {
-	return d.album.UpdatedAt
+	return d.lastUpdate
 }
 
 func (d *discArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {