diff --git a/frontend/openchat-client/src/utils/chat.ts b/frontend/openchat-client/src/utils/chat.ts
index 5a810541b7..1071e773e0 100644
--- a/frontend/openchat-client/src/utils/chat.ts
+++ b/frontend/openchat-client/src/utils/chat.ts
@@ -62,6 +62,7 @@ import type { TypersByKey } from "../stores/typing";
 import { tallyKey } from "../stores/proposalTallies";
 import { hasOwnerRights, isPermitted } from "./permissions";
 import { cryptoLookup } from "../stores/crypto";
+import { bigIntMax } from "./bigint";
 
 const MAX_RTC_CONNECTIONS_PER_CHAT = 10;
 const MERGE_MESSAGES_SENT_BY_SAME_USER_WITHIN_MILLIS = 60 * 1000; // 1 minute
@@ -1268,9 +1269,20 @@ function mergeLocalUpdates(
         ]);
 
         message.thread = {
-            ...current,
-            ...localUpdates.threadSummary,
             participantIds,
+            followedByMe: localUpdates.threadSummary.followedByMe ?? current.followedByMe,
+            numberOfReplies: Math.max(
+                localUpdates.threadSummary.numberOfReplies ?? 0,
+                current.numberOfReplies,
+            ),
+            latestEventIndex: Math.max(
+                localUpdates.threadSummary.latestEventIndex ?? 0,
+                current.latestEventIndex,
+            ),
+            latestEventTimestamp: bigIntMax(
+                localUpdates.threadSummary.latestEventTimestamp ?? BigInt(0),
+                current.latestEventTimestamp,
+            ),
         };
     }