diff --git a/EIPS/eip-778.md b/EIPS/eip-778.md
index 9e245a34..854c3f82 100644
--- a/EIPS/eip-778.md
+++ b/EIPS/eip-778.md
@@ -64,7 +64,7 @@ preferred. The following keys are pre-defined:
 | Key          | Value                                            |
 |:-------------|:-------------------------------------------------|
 | `id`         | name of identity scheme, e.g. "secp256k1-keccak" |
-| `secp256k1`  | compressed secp256k1 public key                  |
+| `secp256k1`  | compressed secp256k1 public key, 33 bytes        |
 | `ip4`        | IPv4 address, 4 bytes                            |
 | `ip6`        | IPv6 address, 16 bytes                           |
 | `discv5`     | UDP port for discovery v5                        |