diff --git a/src/lib.rs b/src/lib.rs
index d61b6c4..d17bab5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -259,6 +259,7 @@ pub struct IndexError {
 
 /// Port offset in a node
 #[derive(Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub enum PortOffset {
     /// Input to a node
     ///
diff --git a/src/weights.rs b/src/weights.rs
index 27549ae..c9258b5 100644
--- a/src/weights.rs
+++ b/src/weights.rs
@@ -40,11 +40,15 @@
 
 use std::ops::{Index, IndexMut};
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use crate::{NodeIndex, PortIndex, SecondaryMap};
 
 /// Graph component that encodes node and port weights.
 /// Based on two [`SecondaryMap`] containers.
 #[derive(Debug, Clone)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub struct Weights<N, P> {
     /// Node weights.
     pub nodes: SecondaryMap<NodeIndex, N>,