diff --git a/rust/lib.rs b/rust/lib.rs
index cc47458ac..02a6e1cbd 100644
--- a/rust/lib.rs
+++ b/rust/lib.rs
@@ -1,4 +1,4 @@
-use ndarray::ArrayView1;
+use ndarray::{ArrayView1, Axis};
 use numpy::{PyArray2, PyReadonlyArray1};
 use pyo3::{pymodule, types::PyModule, PyResult, Python};
 
@@ -41,11 +41,14 @@ fn _utils_rs<'py>(_py: Python<'py>, m: &'py PyModule) -> PyResult<()> {
         let bls_out = unsafe { PyArray2::new(py, (2, nbls), false) };
         let mut _bls_out = unsafe { bls_out.as_array_mut() };
 
-        (0..nbls).for_each(|cnt| {
-            let ants = bl_fn(&bls_array[cnt]);
-            _bls_out[[0, cnt]] = ants[0];
-            _bls_out[[1, cnt]] = ants[1];
-        });
+        _bls_out
+            .axis_iter_mut(Axis(1))
+            .zip(bls_array)
+            .for_each(|(mut ant_array, bl)| {
+                let ants = bl_fn(bl);
+                ant_array[0] = ants[0];
+                ant_array[1] = ants[1];
+            });
 
         bls_out
     }