diff --git a/lib/hooks/toggle-unread-status.js b/lib/hooks/toggle-unread-status.js
--- a/lib/hooks/toggle-unread-status.js
+++ b/lib/hooks/toggle-unread-status.js
@@ -1,17 +1,24 @@
 // @flow
 
+import invariant from 'invariant';
 import * as React from 'react';
 
 import {
   setThreadUnreadStatusActionTypes,
   useSetThreadUnreadStatus,
 } from '../actions/activity-actions.js';
+import type { OutboundDMOperationSpecification } from '../shared/dm-ops/dm-op-utils';
+import { dmOperationSpecificationTypes } from '../shared/dm-ops/dm-op-utils.js';
+import { useProcessAndSendDMOperation } from '../shared/dm-ops/process-dm-ops.js';
 import type {
   SetThreadUnreadStatusPayload,
   SetThreadUnreadStatusRequest,
 } from '../types/activity-types.js';
+import type { DMChangeThreadReadStatusOperation } from '../types/dm-ops';
 import type { ThreadInfo } from '../types/minimally-encoded-thread-permissions-types.js';
+import { threadTypeIsThick } from '../types/thread-types-enum.js';
 import { useDispatchActionPromise } from '../utils/redux-promise-utils.js';
+import { useSelector } from '../utils/redux-utils.js';
 
 function useToggleUnreadStatus(
   threadInfo: ThreadInfo,
@@ -23,7 +30,36 @@
   const boundSetThreadUnreadStatus: (
     request: SetThreadUnreadStatusRequest,
   ) => Promise<SetThreadUnreadStatusPayload> = useSetThreadUnreadStatus();
+
+  const viewerID = useSelector(
+    state => state.currentUserInfo && state.currentUserInfo.id,
+  );
+  const processAndSendDMOperation = useProcessAndSendDMOperation();
+
   const toggleUnreadStatus = React.useCallback(() => {
+    if (threadTypeIsThick(threadInfo.type)) {
+      invariant(viewerID, 'viewerID must be set');
+      const op: DMChangeThreadReadStatusOperation = {
+        type: 'change_thread_read_status',
+        time: Date.now(),
+        threadID: threadInfo.id,
+        creatorID: viewerID,
+        unread: !currentUser.unread,
+      };
+
+      const opSpecification: OutboundDMOperationSpecification = {
+        type: dmOperationSpecificationTypes.OUTBOUND,
+        op,
+        recipients: {
+          type: 'self_devices',
+        },
+      };
+
+      void processAndSendDMOperation(opSpecification);
+      afterAction();
+      return;
+    }
+
     const request = {
       threadID: threadInfo.id,
       unread: !currentUser.unread,
@@ -40,7 +76,9 @@
     );
     afterAction();
   }, [
-    threadInfo.id,
+    processAndSendDMOperation,
+    viewerID,
+    threadInfo,
     currentUser.unread,
     mostRecentNonLocalMessage,
     dispatchActionPromise,