diff --git a/lib/shared/dm-ops/change-thread-settings-spec.js b/lib/shared/dm-ops/change-thread-settings-spec.js
--- a/lib/shared/dm-ops/change-thread-settings-spec.js
+++ b/lib/shared/dm-ops/change-thread-settings-spec.js
@@ -15,10 +15,7 @@
 import type { RawMessageInfo } from '../../types/message-types';
 import { messageTypes } from '../../types/message-types-enum.js';
 import type { ChangeSettingsMessageData } from '../../types/messages/change-settings.js';
-import type {
-  RawThreadInfo,
-  ThickRawThreadInfo,
-} from '../../types/minimally-encoded-thread-permissions-types.js';
+import type { RawThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
 import type { ClientUpdateInfo } from '../../types/update-types.js';
 import { blobHashFromBlobServiceURI } from '../../utils/blob-service.js';
@@ -74,7 +71,10 @@
   } = {};
 
   const { avatar: avatarObject, ...rest } = threadInfoUpdate;
-  let normalizedThreadInfoUpdate;
+  let normalizedThreadInfoUpdate: {
+    ...DMThreadSettingsChanges,
+    +avatar?: string,
+  };
   if (avatarObject) {
     normalizedThreadInfoUpdate = {
       ...rest,
@@ -89,6 +89,9 @@
 
   Object.keys(normalizedThreadInfoUpdate).forEach(fieldName => {
     const value = normalizedThreadInfoUpdate[fieldName];
+    if (value === undefined) {
+      return;
+    }
     const messageData: ChangeSettingsMessageData = {
       type: messageTypes.CHANGE_SETTINGS,
       threadID,
@@ -155,7 +158,7 @@
         ({ rawMessageInfo }) => rawMessageInfo,
       );
 
-      let threadInfoToUpdate: ThickRawThreadInfo = threadInfo;
+      let threadInfoToUpdate = { ...threadInfo };
       Object.keys(threadInfoUpdate).forEach(fieldName => {
         const timestamp = threadInfoToUpdate.timestamps[fieldName];
         if (timestamp < time) {