diff --git a/CHANGES.md b/CHANGES.md
index a1481f1..6ae8849 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -42,6 +42,8 @@
 
 ### Fixed
 
+- Fix automatic language detection for BM25 ranking #164
+
 - PG-backed test layer: reset zodb_pgjsonb's process-wide
   ``SharedLoadCache`` between tests.  The per-test ``restore()`` rolls
   the database backwards to a snapshot, but ``cacheMinimize()`` /
diff --git a/src/plone/pgcatalog/startup.py b/src/plone/pgcatalog/startup.py
index c0a43a7..4b52e4a 100644
--- a/src/plone/pgcatalog/startup.py
+++ b/src/plone/pgcatalog/startup.py
@@ -76,9 +76,9 @@ def _detect_languages_from_db(db):  # pragma: no cover
             root = conn.root()
             app = root.get("Application", root)
             for obj in app.values():
-                lang_tool = getattr(obj, "portal_languages", None)
-                if lang_tool is not None:
-                    langs = list(lang_tool.getSupportedLanguages())
+                portal_registry = getattr(obj, "portal_registry", None)
+                if portal_registry is not None:
+                    langs = portal_registry.get("plone.available_languages", [])
                     if langs:
                         log.info(
                             "Auto-detected BM25 languages from %s: %s",