diff --git a/supabase/migrations/20260611120000_fix_song_identifiers_album_uniqueness.sql b/supabase/migrations/20260611120000_fix_song_identifiers_album_uniqueness.sql
new file mode 100644
index 0000000..46e8077
--- /dev/null
+++ b/supabase/migrations/20260611120000_fix_song_identifiers_album_uniqueness.sql
@@ -0,0 +1,33 @@
+-- Fix (recoupable/chat#1794): the unique constraint on song_identifiers was
+-- (platform, identifier_type, value), which is right for track ids (one
+-- external id = one recording) but wrong for album ids — an album contains
+-- many songs, so (spotify, album_id, <album>) must exist once PER SONG.
+-- The old constraint silently capped every album at one mapped song, which is
+-- why GET /playcounts served 1 of 18 tracks.
+--
+-- The old constraint was declared inline in 20260610010000, so its name is
+-- Postgres-generated — drop the table's (single) unique constraint by lookup
+-- instead of by name.
+
+DO $$
+DECLARE
+  old_constraint text;
+BEGIN
+  SELECT conname INTO old_constraint
+  FROM pg_constraint
+  WHERE conrelid = 'public.song_identifiers'::regclass
+    AND contype = 'u';
+
+  IF old_constraint IS NOT NULL THEN
+    EXECUTE format('ALTER TABLE public.song_identifiers DROP CONSTRAINT %I', old_constraint);
+  END IF;
+END $$;
+
+-- New uniqueness: one mapping per (song, platform, identifier_type, value).
+ALTER TABLE public.song_identifiers
+  ADD CONSTRAINT song_identifiers_song_platform_type_value_unique
+  UNIQUE (song, platform, identifier_type, value);
+
+-- Reverse lookups (value -> songs) keep an index, now non-unique.
+CREATE INDEX idx_song_identifiers_lookup
+  ON public.song_identifiers (platform, identifier_type, value);