diff --git a/adapters/lastfm/agent.go b/adapters/lastfm/agent.go
index 98850fdde..f967595e3 100644
--- a/adapters/lastfm/agent.go
+++ b/adapters/lastfm/agent.go
@@ -291,12 +291,13 @@ func (l *lastfmAgent) GetArtistImages(ctx context.Context, _, name, mbid string)
 func (l *lastfmAgent) callAlbumGetInfo(ctx context.Context, name, artist, lang string) (*Album, error) {
 	a, err := l.client.albumGetInfo(ctx, name, artist, "", lang)
 	if err != nil {
-		var lfErr *lastFMError
-		if errors.As(err, &lfErr) && lfErr.Code == 6 {
-			log.Debug(ctx, "Album not found", "album", name, "artist", artist, err)
-		} else {
-			log.Error(ctx, "Error calling LastFM/album.getInfo", "album", name, "artist", artist, err)
+		if lfErr, ok := errors.AsType[*lastFMError](err); ok && lfErr.Code == 6 {
+			// A not-found is a definitive absence, not a fault: return the shared sentinel so the
+			// artwork worker's breaker/transient checks don't retry it, and log it at Debug.
+			log.Debug(ctx, "Album not found in Last.fm", "album", name, "artist", artist)
+			return nil, agents.ErrNotFound
 		}
+		log.Error(ctx, "Error calling LastFM/album.getInfo", "album", name, "artist", artist, err)
 		return nil, err
 	}
 	return a, nil
@@ -308,6 +309,12 @@ func (l *lastfmAgent) callArtistGetInfo(ctx context.Context, name string, lang s
 
 	a, err := l.client.artistGetInfo(ctx, name, lang)
 	if err != nil {
+		if lfErr, ok := errors.AsType[*lastFMError](err); ok && lfErr.Code == 6 {
+			// A not-found is a definitive absence, not a fault: return the shared sentinel so it
+			// doesn't trip the artwork worker's breaker, and log at Debug instead of Error.
+			log.Debug(ctx, "Artist not found in Last.fm", "artist", name)
+			return nil, agents.ErrNotFound
+		}
 		log.Error(ctx, "Error calling LastFM/artist.getInfo", "artist", name, err)
 		return nil, err
 	}
diff --git a/adapters/lastfm/agent_test.go b/adapters/lastfm/agent_test.go
index 1d1400620..6e94a075d 100644
--- a/adapters/lastfm/agent_test.go
+++ b/adapters/lastfm/agent_test.go
@@ -576,6 +576,9 @@ var _ = Describe("lastfmAgent", func() {
 			httpClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString(lastfmError6)), StatusCode: 200}
 			_, err := agent.GetAlbumInfo(ctx, "123", "U2", "mbid-1234")
 			Expect(err).To(HaveOccurred())
+			// error 6 is a definitive not-found, so it must satisfy the shared sentinel (else it
+			// would trip the artwork worker's circuit breaker and be retried as a transient fault).
+			Expect(errors.Is(err, agents.ErrNotFound)).To(BeTrue())
 			// No MBID retry: album.getInfo is queried by name+artist only, in a single call.
 			Expect(httpClient.RequestCount).To(Equal(1))
 			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(BeEmpty())
@@ -609,6 +612,14 @@ var _ = Describe("lastfmAgent", func() {
 			Expect(images[0].URL).To(Equal("https://lastfm.freetls.fastly.net/i/u/ar0/818148bf682d429dc21b59a73ef6f68e.png"))
 		})
 
+		It("maps a Last.fm error 6 (artist not found) to the shared not-found sentinel", func() {
+			apiClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString(lastfmError6)), StatusCode: 200}
+			_, err := agent.GetArtistImages(ctx, "123", "Nonexistent Artist", "")
+			// Definitive not-found, not a fault — must satisfy the sentinel through the %w wrap so
+			// runs of missing artists never trip the artwork worker's circuit breaker.
+			Expect(errors.Is(err, agents.ErrNotFound)).To(BeTrue())
+		})
+
 		It("returns empty list if image is the ignored default image", func() {
 			fApi, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
 			apiClient.Res = http.Response{Body: fApi, StatusCode: 200}