diff --git a/src/system/nd.rs b/src/system/nd.rs
index dbad2e2..2944836 100644
--- a/src/system/nd.rs
+++ b/src/system/nd.rs
@@ -2,7 +2,7 @@ use std::ops::Add;
 use num_integer::Integer;
 use rand::Rng;
 use serde::{Serialize, Serializer};
-use serde::ser::SerializeMap;
+use serde::ser::{SerializeMap, SerializeSeq, SerializeStruct};
 use crate::system::GriddedPosition;
 use crate::system::Storage;
 
@@ -48,11 +48,11 @@ impl<const DIM: usize> Add for NDPosition<DIM> {
 
 impl<const DIM: usize> Serialize for NDPosition<DIM> {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
-        let mut map = serializer.serialize_map(Some(DIM))?;
+        let mut ser = serializer.serialize_struct("NDPosition", DIM)?;
         for (i, v) in self.0.iter().enumerate() {
-            map.serialize_entry(&format!("r{}", i), v)?;
+            ser.serialize_field(Box::leak(Box::new(format!("r{i}"))), v)?;
         }
-        map.end()
+        ser.end()
     }
 }