diff --git a/web/redux/community-picker-reducer.js b/web/redux/community-picker-reducer.js
new file mode 100644
--- /dev/null
+++ b/web/redux/community-picker-reducer.js
@@ -0,0 +1,61 @@
+// @flow
+
+import { nonThreadCalendarFilters } from 'lib/selectors/calendar-filter-selectors.js';
+import {
+  type CalendarFilter,
+  calendarThreadFilterTypes,
+} from 'lib/types/filter-types.js';
+import type { ThreadStore } from 'lib/types/thread-types.js';
+
+import {
+  updateCalendarCommunityFilter,
+  clearCalendarCommunityFilter,
+} from './action-types.js';
+import type { Action, CommunityPickerStore } from './redux-setup';
+import { filterThreadIDsBelongingToCommunity } from '../selectors/calendar-selectors.js';
+
+export type ReduceCommunityPickerStoreResult = {
+  +communityPickerStore: CommunityPickerStore,
+  +calendarFilters: $ReadOnlyArray<CalendarFilter>,
+};
+
+export function reduceCommunityPickerStore(
+  communityPickerStore: CommunityPickerStore,
+  calendarFilters: $ReadOnlyArray<CalendarFilter>,
+  threadStore: ThreadStore,
+  action: Action,
+): ReduceCommunityPickerStoreResult {
+  if (action.type === updateCalendarCommunityFilter) {
+    const nonThreadFilters = nonThreadCalendarFilters(calendarFilters);
+
+    const threadIDs = Array.from(
+      filterThreadIDsBelongingToCommunity(
+        action.payload,
+        threadStore.threadInfos,
+      ),
+    );
+    return {
+      calendarFilters: [
+        ...nonThreadFilters,
+        {
+          type: calendarThreadFilterTypes.THREAD_LIST,
+          threadIDs,
+        },
+      ],
+      communityPickerStore: {
+        ...communityPickerStore,
+        calendar: action.payload,
+      },
+    };
+  } else if (action.type === clearCalendarCommunityFilter) {
+    const nonThreadFilters = nonThreadCalendarFilters(calendarFilters);
+    return {
+      calendarFilters: nonThreadFilters,
+      communityPickerStore: {
+        ...communityPickerStore,
+        calendar: null,
+      },
+    };
+  }
+  return { communityPickerStore, calendarFilters };
+}
diff --git a/web/redux/redux-setup.js b/web/redux/redux-setup.js
--- a/web/redux/redux-setup.js
+++ b/web/redux/redux-setup.js
@@ -8,7 +8,6 @@
   deleteAccountActionTypes,
 } from 'lib/actions/user-actions.js';
 import baseReducer from 'lib/reducers/master-reducer.js';
-import { nonThreadCalendarFilters } from 'lib/selectors/calendar-filter-selectors.js';
 import { mostRecentlyReadThreadSelector } from 'lib/selectors/thread-selectors.js';
 import { isLoggedIn } from 'lib/selectors/user-selectors.js';
 import { invalidSessionDowngrade } from 'lib/shared/account-utils.js';
@@ -21,10 +20,7 @@
 import type { DraftStore } from 'lib/types/draft-types.js';
 import type { EnabledApps } from 'lib/types/enabled-apps.js';
 import type { EntryStore } from 'lib/types/entry-types.js';
-import {
-  type CalendarFilter,
-  calendarThreadFilterTypes,
-} from 'lib/types/filter-types.js';
+import { type CalendarFilter } from 'lib/types/filter-types.js';
 import type { LifecycleState } from 'lib/types/lifecycle-state-types.js';
 import type { LoadingStatus } from 'lib/types/loading-types.js';
 import type { MessageStore } from 'lib/types/message-types.js';
@@ -45,6 +41,7 @@
   updateCalendarCommunityFilter,
   clearCalendarCommunityFilter,
 } from './action-types.js';
+import { reduceCommunityPickerStore } from './community-picker-reducer.js';
 import {
   reduceCryptoStore,
   setPrimaryIdentityKeys,
@@ -55,7 +52,6 @@
 import { reduceDeviceID } from './device-id-reducer.js';
 import reduceNavInfo from './nav-reducer.js';
 import { getVisibility } from './visibility.js';
-import { filterThreadIDsBelongingToCommunity } from '../selectors/calendar-selectors.js';
 import { activeThreadSelector } from '../selectors/nav-selectors.js';
 import { type NavInfo } from '../types/nav-types.js';
 
@@ -143,39 +139,6 @@
       ...state,
       windowActive: action.payload,
     });
-  } else if (action.type === updateCalendarCommunityFilter) {
-    const nonThreadFilters = nonThreadCalendarFilters(state.calendarFilters);
-
-    const threadIDs = Array.from(
-      filterThreadIDsBelongingToCommunity(
-        action.payload,
-        state.threadStore.threadInfos,
-      ),
-    );
-    return {
-      ...state,
-      calendarFilters: [
-        ...nonThreadFilters,
-        {
-          type: calendarThreadFilterTypes.THREAD_LIST,
-          threadIDs,
-        },
-      ],
-      communityPickerStore: {
-        ...state.communityPickerStore,
-        calendar: action.payload,
-      },
-    };
-  } else if (action.type === clearCalendarCommunityFilter) {
-    const nonThreadFilters = nonThreadCalendarFilters(state.calendarFilters);
-    return {
-      ...state,
-      calendarFilters: nonThreadFilters,
-      communityPickerStore: {
-        ...state.communityPickerStore,
-        calendar: null,
-      },
-    };
   } else if (action.type === setNewSessionActionType) {
     if (
       invalidSessionDowngrade(
@@ -213,11 +176,20 @@
     action.type !== setPrimaryIdentityKeys &&
     action.type !== setNotificationIdentityKeys &&
     action.type !== setPickledPrimaryAccount &&
-    action.type !== setPickledNotificationAccount
+    action.type !== setPickledNotificationAccount &&
+    action.type !== updateCalendarCommunityFilter &&
+    action.type !== clearCalendarCommunityFilter
   ) {
     state = baseReducer(state, action).state;
   }
 
+  const { communityPickerStore, calendarFilters } = reduceCommunityPickerStore(
+    state.communityPickerStore,
+    state.calendarFilters,
+    state.threadStore,
+    action,
+  );
+
   state = {
     ...state,
     navInfo: reduceNavInfo(
@@ -227,6 +199,8 @@
     ),
     deviceID: reduceDeviceID(state.deviceID, action),
     cryptoStore: reduceCryptoStore(state.cryptoStore, action),
+    communityPickerStore,
+    calendarFilters,
   };
 
   return validateState(oldState, state);