diff --git a/SqueezeWave/glow.py b/SqueezeWave/glow.py
index 36199dc..664b7a4 100644
--- a/SqueezeWave/glow.py
+++ b/SqueezeWave/glow.py
@@ -185,6 +185,9 @@ class SqueezeWave(torch.nn.Module):
                  n_early_size, WN_config):
         super(SqueezeWave, self).__init__()        
         assert(n_audio_channel % 2 == 0)
+        self.upsample = torch.nn.ConvTranspose1d(n_mel_channels,
+                                                 n_mel_channels,
+                                                 1024, stride=256)
         self.n_flows = n_flows
         self.n_audio_channel = n_audio_channel
         self.n_early_every = n_early_every