diff --git a/src/grid_impl/grid.rs b/src/grid_impl/grid.rs
index be4c557..6b0750a 100644
--- a/src/grid_impl/grid.rs
+++ b/src/grid_impl/grid.rs
@@ -206,7 +206,7 @@ mod test {
         let grid = SerialGrid::<f64>::new(
             vec![
                 -1.0, 0.0, 0.0, -0.5, 0.0, 0.2, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 2.0, 0.0, 0.0,
-                -0.7071, 0.7071, 0.0, 0.0, 0.5, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0,
+                -f64::consts::FRAC_1_SQRT_2, f64::consts::FRAC_1_SQRT_2, 0.0, 0.0, 0.5, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0,
             ],
             3,
             &[0, 2, 7, 6, 5, 1, 2, 3, 7, 8, 3, 4, 8],