diff --git a/src/lib.rs b/src/lib.rs
index 59b45e1..b47ee68 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -145,7 +145,7 @@ impl PublicKey {
 }
 
 /// A public key share.
-#[derive(Deserialize, Serialize, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)]
+#[derive(Deserialize, Serialize, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct PublicKeyShare(PublicKey);
 
 impl fmt::Debug for PublicKeyShare {