diff --git a/lib/selectors/thread-selectors.js b/lib/selectors/thread-selectors.js
--- a/lib/selectors/thread-selectors.js
+++ b/lib/selectors/thread-selectors.js
@@ -303,7 +303,7 @@
   baseOtherUsersButNoOtherAdmins,
 );
 
-function mostRecentReadThread(
+function mostRecentlyReadThread(
   messageStore: MessageStore,
   threadInfos: { +[id: string]: RawThreadInfo },
 ): ?string {
@@ -334,12 +334,12 @@
   return mostRecent ? mostRecent.threadID : null;
 }
 
-const mostRecentReadThreadSelector: (
+const mostRecentlyReadThreadSelector: (
   state: BaseAppState<*>,
 ) => ?string = createSelector(
   (state: BaseAppState<*>) => state.messageStore,
   (state: BaseAppState<*>) => state.threadStore.threadInfos,
-  mostRecentReadThread,
+  mostRecentlyReadThread,
 );
 
 const threadInfoFromSourceMessageIDSelector: (
@@ -406,8 +406,8 @@
   unreadCount,
   unreadBackgroundCount,
   otherUsersButNoOtherAdmins,
-  mostRecentReadThread,
-  mostRecentReadThreadSelector,
+  mostRecentlyReadThread,
+  mostRecentlyReadThreadSelector,
   sidebarInfoSelector,
   threadInfoFromSourceMessageIDSelector,
   locallyUniqueToRealizedThreadIDsSelector,
diff --git a/server/src/responders/website-responders.js b/server/src/responders/website-responders.js
--- a/server/src/responders/website-responders.js
+++ b/server/src/responders/website-responders.js
@@ -13,7 +13,7 @@
 
 import { daysToEntriesFromEntryInfos } from 'lib/reducers/entry-reducer';
 import { freshMessageStore } from 'lib/reducers/message-reducer';
-import { mostRecentReadThread } from 'lib/selectors/thread-selectors';
+import { mostRecentlyReadThread } from 'lib/selectors/thread-selectors';
 import { mostRecentMessageTimestamp } from 'lib/shared/message-utils';
 import { threadHasPermission } from 'lib/shared/thread-utils';
 import { defaultWebEnabledApps } from 'lib/types/enabled-apps';
@@ -202,7 +202,10 @@
     }
 
     if (!finalNavInfo.activeChatThreadID) {
-      const mostRecentThread = mostRecentReadThread(messageStore, threadInfos);
+      const mostRecentThread = mostRecentlyReadThread(
+        messageStore,
+        threadInfos,
+      );
       if (mostRecentThread) {
         finalNavInfo.activeChatThreadID = mostRecentThread;
       }
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
@@ -7,7 +7,7 @@
   deleteAccountActionTypes,
 } from 'lib/actions/user-actions';
 import baseReducer from 'lib/reducers/master-reducer';
-import { mostRecentReadThreadSelector } from 'lib/selectors/thread-selectors';
+import { mostRecentlyReadThreadSelector } from 'lib/selectors/thread-selectors';
 import { invalidSessionDowngrade } from 'lib/shared/account-utils';
 import type { Shape } from 'lib/types/core';
 import type { EnabledApps } from 'lib/types/enabled-apps';
@@ -144,7 +144,7 @@
       ...state,
       navInfo: {
         ...state.navInfo,
-        activeChatThreadID: mostRecentReadThreadSelector(state),
+        activeChatThreadID: mostRecentlyReadThreadSelector(state),
       },
     };
   }
diff --git a/web/sidebar/app-switcher.react.js b/web/sidebar/app-switcher.react.js
--- a/web/sidebar/app-switcher.react.js
+++ b/web/sidebar/app-switcher.react.js
@@ -5,7 +5,7 @@
 import { useDispatch } from 'react-redux';
 
 import {
-  mostRecentReadThreadSelector,
+  mostRecentlyReadThreadSelector,
   unreadCount,
 } from 'lib/selectors/thread-selectors';
 
@@ -19,7 +19,7 @@
   const activeChatThreadID = useSelector(
     state => state.navInfo.activeChatThreadID,
   );
-  const mostRecentReadThread = useSelector(mostRecentReadThreadSelector);
+  const mostRecentlyReadThread = useSelector(mostRecentlyReadThreadSelector);
   const activeThreadCurrentlyUnread = useSelector(
     state =>
       !activeChatThreadID ||
@@ -36,7 +36,7 @@
         payload: {
           tab: 'chat',
           activeChatThreadID: activeThreadCurrentlyUnread
-            ? mostRecentReadThread
+            ? mostRecentlyReadThread
             : activeChatThreadID,
         },
       });
@@ -44,7 +44,7 @@
     [
       dispatch,
       activeThreadCurrentlyUnread,
-      mostRecentReadThread,
+      mostRecentlyReadThread,
       activeChatThreadID,
     ],
   );