diff --git a/crates/accelerate/src/sparse_pauli_op.rs b/crates/accelerate/src/sparse_pauli_op.rs
index abfe8536f893..aa97dd64b180 100644
--- a/crates/accelerate/src/sparse_pauli_op.rs
+++ b/crates/accelerate/src/sparse_pauli_op.rs
@@ -97,9 +97,7 @@ pub fn decompose_dense(
     operator: PyReadonlyArray2<Complex64>,
     tolerance: f64,
 ) -> PyResult<ZXPaulis> {
-    // Can't use `{integer}::ilog2` until Rust 1.67+.
-    let ilog2 = |val: usize| std::mem::size_of::<usize>() * 8 - val.leading_zeros() as usize - 1;
-    let num_qubits = ilog2(operator.shape()[0]);
+    let num_qubits = operator.shape()[0].ilog2() as usize;
     let size = 1 << num_qubits;
     if operator.shape() != [size, size] {
         return Err(PyValueError::new_err(format!(