diff --git a/candle-core/src/tensor.rs b/candle-core/src/tensor.rs
index 5d0f47c9..5f0b6df9 100644
--- a/candle-core/src/tensor.rs
+++ b/candle-core/src/tensor.rs
@@ -821,13 +821,14 @@ impl Tensor {
     where
         D: Dim + Clone,
     {
-        let dim_size = self.dim(dim.clone())?;
+        let dim = dim.to_index(self.shape(), "roll")?;
+        let dim_size = self.dim(dim)?;
         let shift = shift.rem_euclid(dim_size as i32) as usize;
         if shift == 0 {
-            return Ok(self.clone());
+            Ok(self.clone())
         } else {
-            let a = self.narrow(dim.clone(), 0, dim_size - shift)?;
-            let b = self.narrow(dim.clone(), dim_size - shift, shift)?;
+            let a = self.narrow(dim, 0, dim_size - shift)?;
+            let b = self.narrow(dim, dim_size - shift, shift)?;
             Tensor::cat(&[&b, &a], dim)
         }
     }