diff --git a/fft_conv_pytorch/fft_conv.py b/fft_conv_pytorch/fft_conv.py
index 81a181e..3f59e6f 100644
--- a/fft_conv_pytorch/fft_conv.py
+++ b/fft_conv_pytorch/fft_conv.py
@@ -132,10 +132,12 @@ def fft_conv(
     output = irfftn(output_fr, dim=tuple(range(2, signal.ndim)))
 
     # Remove extra padded values
-    crop_slices = [slice(None), slice(None)] + [
-        slice(0, (signal_size[i] - kernel.size(i) + 1), stride_[i - 2])
-        for i in range(2, signal.ndim)
-    ]
+    crop_slices = tuple(
+        [slice(None), slice(None)] + [
+            slice(0, (signal_size[i] - kernel.size(i) + 1), stride_[i - 2])
+            for i in range(2, signal.ndim)
+        ]
+    )
     output = output[crop_slices].contiguous()
 
     # Optionally, add a bias term before returning.