diff --git a/core/src/peer_id.rs b/core/src/peer_id.rs
index a70d8f68..014f1fc2 100644
--- a/core/src/peer_id.rs
+++ b/core/src/peer_id.rs
@@ -34,8 +34,8 @@ const MAX_INLINE_KEY_LENGTH: usize = 42;
 
 /// Identifier of a peer of the network.
 ///
-/// The data is a multihash of the public key of the peer.
-/// See the [spec](https://github.com/libp2p/specs/blob/master/peer-ids/peer-ids.md) for more information.
+/// The data is a CIDv0 compatible multihash of the protobuf encoded public key of the peer
+/// as specified in [specs/peer-ids](https://github.com/libp2p/specs/blob/master/peer-ids/peer-ids.md).
 #[derive(Clone, Copy, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct PeerId {
     multihash: Multihash,