diff --git a/lib/selectors/socket-selectors.js b/lib/selectors/socket-selectors.js
--- a/lib/selectors/socket-selectors.js
+++ b/lib/selectors/socket-selectors.js
@@ -156,6 +156,9 @@
             // the hashes in the background. In this case we return true
             // to skip this state check. Future state checks (after the hash
             // calculation complete) will be handled normally.
+            // Another case when this is null is when we are handling state
+            // sync with a non-authoritative keyserver. We don't want to sync
+            // user store and current user info with such keyservers.
             if (!hashValue) {
               hashResults[key] = true;
             } else {
diff --git a/lib/shared/state-sync/current-user-state-sync-spec.js b/lib/shared/state-sync/current-user-state-sync-spec.js
--- a/lib/shared/state-sync/current-user-state-sync-spec.js
+++ b/lib/shared/state-sync/current-user-state-sync-spec.js
@@ -3,8 +3,10 @@
 import { createSelector } from 'reselect';
 
 import type { StateSyncSpec, BoundStateSyncSpec } from './state-sync-spec.js';
+import type { CalendarQuery } from '../../types/entry-types.js';
 import type { AppState } from '../../types/redux-types';
 import { type CurrentUserInfo } from '../../types/user-types.js';
+import { authoritativeKeyserverID } from '../../utils/authoritative-keyserver.js';
 import { hash } from '../../utils/objects.js';
 
 const selector: (
@@ -15,7 +17,12 @@
     (currentUserInfo: ?CurrentUserInfo) => ({
       ...currentUserStateSyncSpec,
       getInfoHash: () => hash(currentUserInfo),
-      getAllInfosHash: () => hash(currentUserInfo),
+      getAllInfosHash: (query: CalendarQuery, keyserverID: string) => {
+        if (keyserverID !== authoritativeKeyserverID()) {
+          return null;
+        }
+        return hash(currentUserInfo);
+      },
       getIDs: () => ([]: string[]),
     }),
   );
diff --git a/lib/shared/state-sync/users-state-sync-spec.js b/lib/shared/state-sync/users-state-sync-spec.js
--- a/lib/shared/state-sync/users-state-sync-spec.js
+++ b/lib/shared/state-sync/users-state-sync-spec.js
@@ -4,6 +4,7 @@
 import { createSelector } from 'reselect';
 
 import type { StateSyncSpec, BoundStateSyncSpec } from './state-sync-spec.js';
+import type { CalendarQuery } from '../../types/entry-types.js';
 import type { AppState } from '../../types/redux-types';
 import {
   type ClientUserInconsistencyReportCreationRequest,
@@ -12,6 +13,7 @@
 import type { ProcessServerRequestAction } from '../../types/request-types.js';
 import { type UserInfo, type UserInfos } from '../../types/user-types.js';
 import { actionLogger } from '../../utils/action-logger.js';
+import { authoritativeKeyserverID } from '../../utils/authoritative-keyserver.js';
 import { getConfig } from '../../utils/config.js';
 import { combineUnorderedHashes, hash } from '../../utils/objects.js';
 import { generateReportID } from '../../utils/report-utils.js';
@@ -28,9 +30,18 @@
   (userInfos: UserInfos) => ({
     ...usersStateSyncSpec,
     getInfoHash: (id: string) => hash(userInfos[id]),
-    getAllInfosHash: () =>
-      combineUnorderedHashes(Object.values(userInfos).map(hash)),
-    getIDs: () => Object.keys(userInfos),
+    getAllInfosHash: (query: CalendarQuery, keyserverID: string) => {
+      if (keyserverID !== authoritativeKeyserverID()) {
+        return null;
+      }
+      return combineUnorderedHashes(Object.values(userInfos).map(hash));
+    },
+    getIDs: (query: CalendarQuery, keyserverID: string) => {
+      if (keyserverID !== authoritativeKeyserverID()) {
+        return null;
+      }
+      return Object.keys(userInfos);
+    },
   }),
 );