diff --git a/tests/tools/test_transcription.py b/tests/tools/test_transcription.py
index e8e925d5314..d5c3903ff13 100644
--- a/tests/tools/test_transcription.py
+++ b/tests/tools/test_transcription.py
@@ -217,6 +217,28 @@ class TestTranscribeLocal:
         assert result["success"] is True
         assert "initial_prompt" not in mock_model.transcribe.call_args.kwargs
 
+    def test_accepts_null_local_config(self, monkeypatch, tmp_path):
+        monkeypatch.delenv("HERMES_LOCAL_STT_LANGUAGE", raising=False)
+        audio_file = tmp_path / "test.ogg"
+        audio_file.write_bytes(b"fake audio")
+
+        mock_info = MagicMock(language="en", duration=2.5)
+        mock_model = MagicMock()
+        mock_model.transcribe.return_value = ([], mock_info)
+
+        fake_fw = _fake_faster_whisper_module(mock_model)
+        with patch("tools.transcription_tools._HAS_FASTER_WHISPER", True), \
+             patch("tools.transcription_tools._load_stt_config", return_value={
+                 "local": None,
+             }), \
+             patch.dict("sys.modules", {"faster_whisper": fake_fw}), \
+             patch("tools.transcription_tools._local_model", None):
+            from tools.transcription_tools import _transcribe_local
+            result = _transcribe_local(str(audio_file), "base")
+
+        assert result["success"] is True
+        assert mock_model.transcribe.call_args.kwargs == {"beam_size": 5}
+
     def test_not_installed(self):
         with patch("tools.transcription_tools._HAS_FASTER_WHISPER", False):
             from tools.transcription_tools import _transcribe_local