diff --git a/CHANGES.md b/CHANGES.md
index a8caa7a..4208033 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,17 @@
 # Changelog
 
+## 1.0.0b67 (unreleased)
+
+### Fixed
+
+- Full-text search now picks up the current site/negotiated language when the
+  query has no explicit `Language` parameter, instead of falling back to the
+  `simple` text-search configuration. On multilingual sites this means BM25 /
+  `tsvector` ranking uses the right language config (stemming, stop words) for
+  queries that don't pass `Language` (e.g. plain `SearchableText` searches).
+  The language is resolved from the request, the context, or the portal default
+  via a small vendored helper (no `plone.api` dependency). #166
+
 ## 1.0.0b66 (2026-06-29)
 
 ### Added
@@ -64,6 +76,7 @@
   fast with a clear hint pointing at the required extra; the S3 path
   raises an actionable error too. #171
 
+
 ## 1.0.0b65
 
 ### Added
@@ -119,6 +132,7 @@
   ``storage.clear_caches()`` after ``restore()``; this requires
   ``zodb-pgjsonb >= 1.13.0`` (the dependency floor is bumped accordingly).
 
+
 ## 1.0.0b64
 
 ### Fixed
diff --git a/src/plone/pgcatalog/query.py b/src/plone/pgcatalog/query.py
index 6a55198..36d3ccc 100644
--- a/src/plone/pgcatalog/query.py
+++ b/src/plone/pgcatalog/query.py
@@ -13,6 +13,7 @@
 from plone.pgcatalog.columns import get_registry
 from plone.pgcatalog.columns import IndexType
 from plone.pgcatalog.columns import validate_identifier
+from plone.pgcatalog.utils import get_current_language
 from psycopg.types.json import Json
 from typing import ClassVar
 
@@ -609,6 +610,12 @@ def _handle_text(self, name, idx_key, spec):
             lang_val = self._query.get("Language")
             if isinstance(lang_val, dict):
                 lang_val = lang_val.get("query", "")
+            if not lang_val:
+                # Try getting the current language from the environment
+                current_language = get_current_language()
+                if current_language is not None:
+                    lang_val = current_language
+
             lang_val = _bool_to_lower_str(lang_val) if lang_val else ""
 
             clause, params, rank_expr = get_backend().build_search_clause(
diff --git a/src/plone/pgcatalog/utils.py b/src/plone/pgcatalog/utils.py
new file mode 100644
index 0000000..cba1c8b
--- /dev/null
+++ b/src/plone/pgcatalog/utils.py
@@ -0,0 +1,41 @@
+# Implementation taken from plone.api.portal to avoid
+# having plone.api as a dependency
+
+from Acquisition import aq_inner
+from plone.registry.interfaces import IRegistry
+from zope.component import getUtility
+from zope.globalrequest import getRequest
+
+
+def get_default_language():
+    """Return the default language.
+
+    :returns: language identifier
+    :rtype: string
+    :Example: :ref:`portal-get-default-language-example`
+    """
+    from plone.i18n.interfaces import ILanguageSchema
+
+    registry = getUtility(IRegistry)
+    settings = registry.forInterface(ILanguageSchema, prefix="plone")
+    return settings.default_language
+
+
+def get_current_language(context=None):
+    """Return the current negotiated language.
+
+    :param context: context object
+    :type context: object
+    :returns: language identifier
+    :rtype: string
+    :Example: :ref:`portal-get-current-language-example`
+    """
+    request = getRequest()
+    if request is not None:
+        return (
+            request.get("LANGUAGE", None)
+            or (context and aq_inner(context).Language())
+            or get_default_language()
+        )
+
+    return None
diff --git a/tests/test_query.py b/tests/test_query.py
index 07e91f7..5ccef27 100644
--- a/tests/test_query.py
+++ b/tests/test_query.py
@@ -1378,3 +1378,47 @@ def test_empty_when_only_unknown_keys(self):
         assert (
             strip_non_index_keys({"metadata_fields": ["Title"]}, ["portal_type"]) == {}
         )
+
+
+class TestSearchableTextCurrentLanguage:
+    """#166: when the query has no Language, fall back to the current/site
+    language for the search text-search configuration instead of 'simple'."""
+
+    def test_uses_current_language_when_language_absent(self, monkeypatch):
+        import plone.pgcatalog.query as q
+
+        monkeypatch.setattr(q, "get_current_language", lambda *a, **k: "de")
+        qr = build_query({"SearchableText": "hallo"})
+        assert [v for v in qr["params"].values() if v == "de"], qr["params"]
+
+    def test_explicit_language_wins_over_current_language(self, monkeypatch):
+        import plone.pgcatalog.query as q
+
+        monkeypatch.setattr(q, "get_current_language", lambda *a, **k: "de")
+        qr = build_query({"SearchableText": "bonjour", "Language": "fr"})
+        assert [v for v in qr["params"].values() if v == "fr"], qr["params"]
+        assert not [v for v in qr["params"].values() if v == "de"], qr["params"]
+
+    def test_no_request_falls_back_to_simple(self, monkeypatch):
+        """No current language available → empty string ('simple' config)."""
+        import plone.pgcatalog.query as q
+
+        monkeypatch.setattr(q, "get_current_language", lambda *a, **k: None)
+        qr = build_query({"SearchableText": "hello"})
+        assert [v for v in qr["params"].values() if v == ""], qr["params"]
+
+
+class TestGetCurrentLanguage:
+    """Unit tests for the vendored get_current_language helper (#166)."""
+
+    def test_returns_none_without_request(self, monkeypatch):
+        import plone.pgcatalog.utils as u
+
+        monkeypatch.setattr(u, "getRequest", lambda: None)
+        assert u.get_current_language() is None
+
+    def test_returns_request_language(self, monkeypatch):
+        import plone.pgcatalog.utils as u
+
+        monkeypatch.setattr(u, "getRequest", lambda: {"LANGUAGE": "eu"})
+        assert u.get_current_language() == "eu"