diff --git a/enhancer/utils/transforms.py b/enhancer/utils/transforms.py
index bbbae90..acfc323 100644
--- a/enhancer/utils/transforms.py
+++ b/enhancer/utils/transforms.py
@@ -14,9 +14,12 @@ class ConvFFT(nn.Module):
         nfft: Optional[int] = None,
         window: str = "hamming",
     ):
+        super().__init__()
         self.window_len = window_len
         self.nfft = nfft if nfft else np.int(2 ** np.ceil(np.log2(window_len)))
-        self.window = get_window(window, window_len)
+        self.window = torch.from_numpy(
+            get_window(window, window_len).astype("float32")
+        )
 
     @property
     def init_kernel(self):
@@ -24,8 +27,9 @@ class ConvFFT(nn.Module):
         fourier_basis = np.fft.rfft(np.eye(self.nfft))[: self.window_len]
         real, imag = np.real(fourier_basis), np.imag(fourier_basis)
         kernel = np.concatenate([real, imag], 1).T
+        kernel = torch.from_numpy(kernel.astype("float32")).unsqueeze(1)
         kernel *= self.window
-        return torch.from_numpy(kernel)
+        return kernel
 
 
 class ConvSTFT(ConvFFT):
@@ -36,9 +40,7 @@ class ConvSTFT(ConvFFT):
         nfft: Optional[int] = None,
         window: str = "hamming",
     ):
-        super(self, ConvSTFT).__init__(
-            window_len=window_len, nfft=nfft, window=window
-        )
+        super().__init__(window_len=window_len, nfft=nfft, window=window)
         self.hop_size = hop_size if hop_size else window_len // 2
         self.register_buffer("weight", self.init_kernel)
 
@@ -69,12 +71,10 @@ class ConviSTFT(ConvFFT):
         nfft: Optional[int] = None,
         window: str = "hamming",
     ):
-        super(self, ConvSTFT).__init__(
-            window_len=window_len, nfft=nfft, window=window
-        )
+        super().__init__(window_len=window_len, nfft=nfft, window=window)
         self.hop_size = hop_size if hop_size else window_len // 2
         self.register_buffer("weight", self.init_kernel)
-        self.register_buffer("enframe", np.eye(window_len).unsqueeze(1))
+        self.register_buffer("enframe", torch.eye(window_len).unsqueeze(1))
 
     def forward(self, input, phase=None):
 
@@ -82,3 +82,10 @@ class ConviSTFT(ConvFFT):
             real = input * torch.cos(phase)
             imag = input * torch.sin(phase)
             input = torch.cat([real, imag], 1)
+        out = F.conv_transpose1d(input, self.weight, stride=self.hop_size)
+        coeff = self.window.unsqueeze(1).repeat(1, 1, input.size(-1)) ** 2
+        coeff = F.conv_transpose1d(coeff, self.enframe, stride=self.hop_size)
+        out = out / coeff
+        pad = self.window_len - self.hop_size
+        out = out[..., pad:-pad]
+        return out