diff --git a/keyserver/src/cron/cron.js b/keyserver/src/cron/cron.js
index 6a3b2358d..4c6243816 100644
--- a/keyserver/src/cron/cron.js
+++ b/keyserver/src/cron/cron.js
@@ -1,74 +1,76 @@
 // @flow
 
 import cluster from 'cluster';
 import schedule from 'node-schedule';
 
 import { deleteOrphanedActivity } from '../deleters/activity-deleters';
 import { deleteExpiredCookies } from '../deleters/cookie-deleters';
 import { deleteOrphanedDays } from '../deleters/day-deleters';
 import { deleteOrphanedEntries } from '../deleters/entry-deleters';
 import { deleteOrphanedMemberships } from '../deleters/membership-deleters';
 import { deleteOrphanedMessages } from '../deleters/message-deleters';
 import { deleteOrphanedNotifs } from '../deleters/notif-deleters';
 import { deleteOrphanedRevisions } from '../deleters/revision-deleters';
 import { deleteOrphanedRoles } from '../deleters/role-deleters';
 import {
   deleteOrphanedSessions,
   deleteOldWebSessions,
 } from '../deleters/session-deleters';
+import { deleteStaleSIWENonceEntries } from '../deleters/siwe-nonce-deleters.js';
 import { deleteInaccessibleThreads } from '../deleters/thread-deleters';
 import { deleteExpiredUpdates } from '../deleters/update-deleters';
 import { deleteUnassignedUploads } from '../deleters/upload-deleters';
 import { backupDB } from './backups';
 import { updateAndReloadGeoipDB } from './update-geoip-db';
 
 if (cluster.isMaster) {
   schedule.scheduleJob(
     '30 3 * * *', // every day at 3:30 AM Pacific Time
     async () => {
       try {
         // Do everything one at a time to reduce load since we're in no hurry,
         // and since some queries depend on previous ones.
         await deleteExpiredCookies();
         await deleteInaccessibleThreads();
         await deleteOrphanedMemberships();
         await deleteOrphanedDays();
         await deleteOrphanedEntries();
         await deleteOrphanedRevisions();
         await deleteOrphanedRoles();
         await deleteOrphanedMessages();
         await deleteOrphanedActivity();
         await deleteOrphanedNotifs();
         await deleteOrphanedSessions();
         await deleteOldWebSessions();
         await deleteExpiredUpdates();
         await deleteUnassignedUploads();
+        await deleteStaleSIWENonceEntries();
       } catch (e) {
         console.warn('encountered error while trying to clean database', e);
       }
     },
   );
   schedule.scheduleJob(
     '0 */4 * * *', // every four hours
     async () => {
       try {
         await backupDB();
       } catch (e) {
         console.warn('encountered error while trying to backup database', e);
       }
     },
   );
   schedule.scheduleJob(
     '0 3 ? * 0', // every Sunday at 3:00 AM Pacific Time
     async () => {
       try {
         await updateAndReloadGeoipDB();
       } catch (e) {
         console.warn(
           'encountered error while trying to update GeoIP database',
           e,
         );
       }
     },
   );
 }
diff --git a/keyserver/src/deleters/siwe-nonce-deleters.js b/keyserver/src/deleters/siwe-nonce-deleters.js
new file mode 100644
index 000000000..002246ec8
--- /dev/null
+++ b/keyserver/src/deleters/siwe-nonce-deleters.js
@@ -0,0 +1,17 @@
+// @flow
+
+import { dbQuery, SQL } from '../database/database';
+
+// 30 minutes = 30min * 60sec * 1000ms
+export const nonceLifetime = 30 * 60 * 1000;
+
+async function deleteStaleSIWENonceEntries(): Promise<void> {
+  const earliestValidCreationTime = Date.now() - nonceLifetime;
+  const query = SQL`
+    DELETE FROM siwe_nonces
+      WHERE creation_time < ${earliestValidCreationTime}
+  `;
+  await dbQuery(query);
+}
+
+export { deleteStaleSIWENonceEntries };