diff --git a/web/src/lib/listenbrainz.ts b/web/src/lib/listenbrainz.ts
index 86628af..494e06d 100644
--- a/web/src/lib/listenbrainz.ts
+++ b/web/src/lib/listenbrainz.ts
@@ -1,7 +1,8 @@
 const LB_BASE = process.env.LISTENBRAINZ_URL ?? "https://labs.api.listenbrainz.org";
-// Keep in sync with the worker's _listenbrainz.py default algorithm.
+// Keep in sync with the worker's _listenbrainz.py default algorithm. Must be a
+// permitted enum member of the LB endpoint (invalid strings 400). Verified live 2026-07-12.
 const ALGORITHM =
-  "session_based_days_7500_session_300_contribution_5_threshold_15_limit_50_filter_True_skip_30";
+  "session_based_days_7500_session_300_contribution_3_threshold_10_limit_100_filter_True_skip_30";
 
 export type SimilarArtist = { mbid: string; name: string; score: number };
 
diff --git a/worker/lyra_worker/similarity/_listenbrainz.py b/worker/lyra_worker/similarity/_listenbrainz.py
index 89a93b4..39b0886 100644
--- a/worker/lyra_worker/similarity/_listenbrainz.py
+++ b/worker/lyra_worker/similarity/_listenbrainz.py
@@ -3,11 +3,12 @@ import requests
 from lyra_worker.similarity.base import SimilarArtist
 
 _DEFAULT_URL = "https://labs.api.listenbrainz.org"
-# ListenBrainz Labs similar-artists dataset requires an algorithm parameter.
-# NOTE: confirm this string + response field names against the live API during
-# manual verification; parsing below is defensive if the shape shifts.
+# ListenBrainz Labs similar-artists dataset requires an algorithm parameter whose
+# value must be one of the endpoint's permitted enum members (an invalid string 400s).
+# Verified against the live API 2026-07-12: this algorithm returns rows shaped
+# {artist_mbid, name, comment, score, ...}, which the parser below reads defensively.
 _DEFAULT_ALGORITHM = (
-    "session_based_days_7500_session_300_contribution_5_threshold_15_limit_50_filter_True_skip_30"
+    "session_based_days_7500_session_300_contribution_3_threshold_10_limit_100_filter_True_skip_30"
 )