diff --git a/tests/test_save_audio_validation.py b/tests/test_save_audio_validation.py
new file mode 100644
index 0000000..8b8fbe7
--- /dev/null
+++ b/tests/test_save_audio_validation.py
@@ -0,0 +1,13 @@
+import os
+import tempfile
+import pytest
+import torch
+from utils import save_audio
+
+
+def test_save_audio_rejects_non_1d_input():
+    with tempfile.TemporaryDirectory() as tmpdir:
+        path = os.path.join(tmpdir, "audio.wav")
+        two_d = torch.zeros(2, 100)
+        with pytest.raises(ValueError, match="expects 1D audio"):
+            save_audio(two_d, path, sr=22050)
diff --git a/utils.py b/utils.py
index 888ea89..82a3857 100644
--- a/utils.py
+++ b/utils.py
@@ -94,6 +94,8 @@ def scan_checkpoint(cp_dir, prefix, renamed_file=None):
 
 def save_audio(audio, path, sr):
     # wav: torch with 1d shape
+    if audio.dim() != 1:
+        raise ValueError(f"save_audio expects 1D audio, got shape {audio.shape}")
     audio = audio * MAX_WAV_VALUE
     audio = audio.cpu().numpy().astype("int16")
     write(path, sr, audio)