diff --git a/lib/reducers/master-reducer.js b/lib/reducers/master-reducer.js
--- a/lib/reducers/master-reducer.js
+++ b/lib/reducers/master-reducer.js
@@ -181,6 +181,11 @@
     action,
   );
 
+  const { threadActivityStore } = reduceThreadActivity(
+    state.threadActivityStore,
+    action,
+  );
+
   return {
     state: {
       ...state,
@@ -212,10 +217,6 @@
       ),
       inviteLinksStore: reduceInviteLinks(state.inviteLinksStore, action),
       keyserverStore,
-      threadActivityStore: reduceThreadActivity(
-        state.threadActivityStore,
-        action,
-      ),
       integrityStore,
       globalThemeInfo: reduceGlobalThemeInfo(state.globalThemeInfo, action),
       customServer: reduceCustomerServer(state.customServer, action),
@@ -223,6 +224,7 @@
       dbOpsStore: reduceDBOpsStore(state.dbOpsStore, action),
       syncedMetadataStore,
       auxUserStore,
+      threadActivityStore,
     },
     storeOperations: {
       draftStoreOperations,
diff --git a/lib/reducers/thread-activity-reducer.js b/lib/reducers/thread-activity-reducer.js
--- a/lib/reducers/thread-activity-reducer.js
+++ b/lib/reducers/thread-activity-reducer.js
@@ -17,7 +17,10 @@
 import { deleteKeyserverAccountActionTypes } from '../actions/user-actions.js';
 import { extractKeyserverIDFromID } from '../keyserver-conn/keyserver-call-utils.js';
 import { setNewSessionActionType } from '../keyserver-conn/keyserver-conn-types.js';
-import { threadActivityStoreOpsHandlers } from '../ops/thread-activity-store-ops.js';
+import {
+  threadActivityStoreOpsHandlers,
+  type ThreadActivityStoreOperation,
+} from '../ops/thread-activity-store-ops.js';
 import type { BaseAction } from '../types/redux-types.js';
 import { incrementalStateSyncActionType } from '../types/socket-types.js';
 import type { ThreadActivityStore } from '../types/thread-activity-types.js';
@@ -32,7 +35,10 @@
 function reduceThreadActivity(
   state: ThreadActivityStore,
   action: BaseAction,
-): ThreadActivityStore {
+): {
+  +threadActivityStore: ThreadActivityStore,
+  +threadActivityStoreOperations: $ReadOnlyArray<ThreadActivityStoreOperation>,
+} {
   if (action.type === updateThreadLastNavigatedActionType) {
     const { threadID, time } = action.payload;
     const replaceOperation = {
@@ -45,7 +51,10 @@
         },
       },
     };
-    return processStoreOps(state, [replaceOperation]);
+    return {
+      threadActivityStore: processStoreOps(state, [replaceOperation]),
+      threadActivityStoreOperations: [replaceOperation],
+    };
   } else if (action.type === messageStorePruneActionType) {
     const now = Date.now();
     const replaceOperations = [];
@@ -62,7 +71,10 @@
       };
       replaceOperations.push(replaceOperation);
     }
-    return processStoreOps(state, replaceOperations);
+    return {
+      threadActivityStore: processStoreOps(state, replaceOperations),
+      threadActivityStoreOperations: replaceOperations,
+    };
   } else if (
     action.type === joinThreadActionTypes.success ||
     action.type === leaveThreadActionTypes.success ||
@@ -78,14 +90,20 @@
   ) {
     const { newUpdates } = action.payload.updatesResult;
     if (newUpdates.length === 0) {
-      return state;
+      return {
+        threadActivityStore: state,
+        threadActivityStoreOperations: [],
+      };
     }
 
     const deleteThreadUpdates = newUpdates.filter(
       (update: ClientUpdateInfo) => update.type === updateTypes.DELETE_THREAD,
     );
     if (deleteThreadUpdates.length === 0) {
-      return state;
+      return {
+        threadActivityStore: state,
+        threadActivityStoreOperations: [],
+      };
     }
 
     const threadIDsToRemove = [];
@@ -102,7 +120,10 @@
         ids: threadIDsToRemove,
       },
     };
-    return processStoreOps(state, [removeOperation]);
+    return {
+      threadActivityStore: processStoreOps(state, [removeOperation]),
+      threadActivityStoreOperations: [removeOperation],
+    };
   } else if (action.type === deleteKeyserverAccountActionTypes.success) {
     const threadIDsToRemove = [];
     const keyserverIDsSet = new Set<string>(action.payload.keyserverIDs);
@@ -121,7 +142,10 @@
       },
     };
 
-    return processStoreOps(state, [removeOperation]);
+    return {
+      threadActivityStore: processStoreOps(state, [removeOperation]),
+      threadActivityStoreOperations: [removeOperation],
+    };
   } else if (
     action.type === setNewSessionActionType &&
     action.payload.sessionChange.cookieInvalidated
@@ -143,9 +167,15 @@
       },
     };
 
-    return processStoreOps(state, [removeOperation]);
+    return {
+      threadActivityStore: processStoreOps(state, [removeOperation]),
+      threadActivityStoreOperations: [removeOperation],
+    };
   }
-  return state;
+  return {
+    threadActivityStore: state,
+    threadActivityStoreOperations: [],
+  };
 }
 
 export { reduceThreadActivity };
diff --git a/lib/reducers/thread-activity-reducer.test.js b/lib/reducers/thread-activity-reducer.test.js
--- a/lib/reducers/thread-activity-reducer.test.js
+++ b/lib/reducers/thread-activity-reducer.test.js
@@ -36,7 +36,7 @@
       },
     };
     const result = reduceThreadActivity(initialState, action);
-    expect(result).toEqual(expectedState);
+    expect(result.threadActivityStore).toEqual(expectedState);
   });
 
   test('returns the initial state if the action type is not recognized', () => {
@@ -65,7 +65,7 @@
       },
     };
     const result = reduceThreadActivity(initialState, action);
-    expect(result).toEqual(expectedState);
+    expect(result.threadActivityStore).toEqual(expectedState);
   });
 
   test('removes threads of keyserver the user has disconnected from', () => {
@@ -106,6 +106,8 @@
       },
     };
 
-    expect(reduceThreadActivity(threads, action)).toEqual(threads3);
+    expect(reduceThreadActivity(threads, action).threadActivityStore).toEqual(
+      threads3,
+    );
   });
 });