diff --git a/TTS/vocoder/layers/losses.py b/TTS/vocoder/layers/losses.py
index d49f2725..1107b3c5 100644
--- a/TTS/vocoder/layers/losses.py
+++ b/TTS/vocoder/layers/losses.py
@@ -11,7 +11,8 @@ class TorchSTFT(nn.Module):
         self.n_fft = n_fft
         self.hop_length = hop_length
         self.win_length = win_length
-        self.window = nn.Parameter(getattr(torch, window)(win_length))
+        self.window = nn.Parameter(getattr(torch, window)(win_length),
+                                   requires_grad=False)
 
     def __call__(self, x):
         # B x D x T x 2