diff --git a/keyserver/src/responders/user-responders.js b/keyserver/src/responders/user-responders.js
--- a/keyserver/src/responders/user-responders.js
+++ b/keyserver/src/responders/user-responders.js
@@ -194,6 +194,7 @@
   calendarQuery: t.maybe(newEntryQueryInputValidator),
   deviceTokenUpdateRequest: t.maybe(deviceTokenUpdateRequestInputValidator),
   platformDetails: tPlatformDetails,
+  primaryIdentityPublicKey: t.maybe(tRegex(primaryIdentityPublicKeyRegex)),
 });
 
 async function accountCreationResponder(