diff --git a/py/expression_handlers.py b/py/expression_handlers.py
index 2663942..d669c0a 100644
--- a/py/expression_handlers.py
+++ b/py/expression_handlers.py
@@ -102,11 +102,11 @@ class FlipHandler(NormHandler):
             return torch.flip(tensor, (dim,))
         result = tensor.detach().clone()
         pivot = tensor.shape[dim] // 2
-        out_slice = (
+        out_slice = tuple(
             np.s_[:] if d != dim else np.s_[pivot:] for d in range(tensor.ndim)
         )
-        in_slice = (np.s_[:] if d != dim else np.s_[:pivot] for d in range(tensor.ndim))
-        result[*out_slice] = torch.flip(tensor[*in_slice], dims=(dim,))
+        in_slice = tuple(np.s_[:] if d != dim else np.s_[:pivot] for d in range(tensor.ndim))
+        result[out_slice] = torch.flip(tensor[in_slice], dims=(dim,))
         return result