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
@@ -15,11 +15,15 @@
 import type { DMChangeThreadSettingsOperation } from '../../types/dm-ops.js';
 import { messageTypes } from '../../types/message-types-enum.js';
 import type { RawMessageInfo } from '../../types/message-types.js';
+import type { AddMembersMessageData } from '../../types/messages/add-members.js';
+import type { ChangeSettingsMessageData } from '../../types/messages/change-settings.js';
 import type { RawThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
+import type { NotificationsCreationData } from '../../types/notif-types.js';
 import type { LegacyRawThreadInfo } from '../../types/thread-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
 import type { ClientUpdateInfo } from '../../types/update-types.js';
 import { values } from '../../utils/objects.js';
+import { firstLine } from '../../utils/string-utils.js';
 
 function createAddMembersOperation(
   dmOperation: DMChangeThreadSettingsOperation,
@@ -166,6 +170,66 @@
         utilities,
       );
     },
+    notificationsCreationData(
+      dmOp: DMChangeThreadSettingsOperation,
+    ): NotificationsCreationData {
+      const {
+        existingThreadDetails: { threadID },
+        editorID: creatorID,
+        time,
+        changes,
+      } = dmOp;
+      const messageDatas: Array<
+        ChangeSettingsMessageData | AddMembersMessageData,
+      > = [];
+
+      const normalizedChanges: {
+        [string]: string,
+      } = {};
+
+      const { name, color, description, avatar, newMemberIDs } = changes;
+
+      if (name) {
+        normalizedChanges.name = firstLine(name);
+      }
+
+      if (color) {
+        normalizedChanges.color = color.toLowerCase();
+      }
+
+      if (description) {
+        normalizedChanges.description = description;
+      }
+
+      if (avatar) {
+        normalizedChanges.avatar = JSON.stringify(avatar);
+      }
+
+      for (const field in normalizedChanges) {
+        const value = normalizedChanges[field];
+        messageDatas.push({
+          type: messageTypes.CHANGE_SETTINGS,
+          threadID,
+          creatorID,
+          time,
+          value,
+          field,
+        });
+      }
+
+      if (newMemberIDs && newMemberIDs.length > 0) {
+        messageDatas.push({
+          type: messageTypes.ADD_MEMBERS,
+          threadID,
+          creatorID,
+          time,
+          addedUserIDs: [...newMemberIDs],
+        });
+      }
+      return {
+        messageDatas,
+      };
+    },
   });
 
 export { changeThreadSettingsSpec };