diff --git a/training/acoustic_task.py b/training/acoustic_task.py
index ca6a71c65..a9f514eac 100644
--- a/training/acoustic_task.py
+++ b/training/acoustic_task.py
@@ -45,7 +45,8 @@ def collater(self, samples):
         tokens = utils.collate_nd([s['tokens'] for s in samples], 0)
         f0 = utils.collate_nd([s['f0'] for s in samples], 0.0)
         mel2ph = utils.collate_nd([s['mel2ph'] for s in samples], 0)
-        mel = utils.collate_nd([s['mel'] for s in samples], 0.0)
+        mel_pad = float(hparams['spec_min'][0]) if hparams.get('spec_min') else -12.0
+        mel = utils.collate_nd([s['mel'] for s in samples], mel_pad)
         batch.update({
             'tokens': tokens,
             'mel2ph': mel2ph,