diff --git a/phiml/math/_ops.py b/phiml/math/_ops.py
index 1106188a..aae2dddc 100644
--- a/phiml/math/_ops.py
+++ b/phiml/math/_ops.py
@@ -265,6 +265,16 @@ def slice_off(x, *slices: Dict[str, Union[slice, int, str]]):
     if not slices:
         return x
     x_shape = shape(x)
+    def to_slices(s):
+        if isinstance(s, Tensor):
+            assert len(s.shape.channel) == 1, f"Indices tensors must have a single channel dim but got {s}"
+            dims = s.shape.channel.item_names[0]
+            indices = s.numpy([..., channel])
+            slices = [{d: i for d, i in zip(dims, idx)} for idx in indices]
+            return slices
+        assert isinstance(s, dict), f"Not a valid slice: {s}"
+        return [s]
+    slices = sum([to_slices(s) for s in slices], [])
     dims = set().union(*[s.keys() for s in slices])
     dims = x_shape.only(dims).names
     depth = max(len(s) for s in slices)