diff --git a/keyserver/src/cron/update-identity-reserved-usernames.js b/keyserver/src/cron/update-identity-reserved-usernames.js
--- a/keyserver/src/cron/update-identity-reserved-usernames.js
+++ b/keyserver/src/cron/update-identity-reserved-usernames.js
@@ -3,6 +3,7 @@
 import { getRustAPI } from 'rust-node-addon';
 
 import type { ReservedUsernameMessage } from 'lib/types/crypto-types.js';
+import { isValidEthereumAddress } from 'lib/utils/siwe-utils.js';
 
 import { fetchAllUsernames } from '../fetchers/user-fetchers.js';
 import { fetchOlmAccount } from '../updaters/olm-account-updater.js';
@@ -13,10 +14,13 @@
     getRustAPI(),
     fetchOlmAccount('content'),
   ]);
+  const filteredUsernames = usernames.filter(
+    username => !isValidEthereumAddress(username),
+  );
   const issuedAt = new Date().toISOString();
   const reservedUsernameMessage: ReservedUsernameMessage = {
     statement: 'Add the following usernames to reserved list',
-    payload: usernames,
+    payload: filteredUsernames,
     issuedAt,
   };
   const stringifiedMessage = JSON.stringify(reservedUsernameMessage);