diff --git a/src/identity/peer.rs b/src/identity/peer.rs
index b6a7fce..06f65f7 100644
--- a/src/identity/peer.rs
+++ b/src/identity/peer.rs
@@ -24,12 +24,22 @@ impl PeerIdentity {
     ///
     /// Note: When only the x-only key is available, the full public key
     /// will be derived assuming even parity for ECDH operations.
+    ///
+    /// Precomputes the even-parity full pubkey eagerly so `pubkey_full()`
+    /// is a constant-time field load. Without this, every send-side
+    /// hot-path caller (per-packet) re-derived the full key, spending
+    /// ~6% of CPU on a secp256k1 EC point parse (`fe_sqrt` + `fe_mul` +
+    /// `ge_set_xo_var`) for what should be a memoized lookup. The same
+    /// EC point parse already runs at construction inside
+    /// `NodeAddr::from_pubkey`, so the cost is paid where it would be
+    /// paid anyway.
     pub fn from_pubkey(pubkey: XOnlyPublicKey) -> Self {
         let node_addr = NodeAddr::from_pubkey(&pubkey);
         let address = FipsAddress::from_node_addr(&node_addr);
+        let pubkey_full = pubkey.public_key(Parity::Even);
         Self {
             pubkey,
-            pubkey_full: None,
+            pubkey_full: Some(pubkey_full),
             node_addr,
             address,
         }