diff --git a/backend/src/services/nextcloud.service.ts b/backend/src/services/nextcloud.service.ts
index 575c4b7..1d450ba 100644
--- a/backend/src/services/nextcloud.service.ts
+++ b/backend/src/services/nextcloud.service.ts
@@ -287,13 +287,15 @@ async function markAsRead(token: string, loginName: string, appPassword: string)
   }
 
   try {
-    await axios.delete(
+    await axios.post(
       `${baseUrl}/ocs/v2.php/apps/spreed/api/v1/chat/${encodeURIComponent(token)}/read`,
+      { lastReadMessage: null },
       {
         headers: {
           'Authorization': `Basic ${Buffer.from(loginName + ':' + appPassword).toString('base64')}`,
           'OCS-APIRequest': 'true',
           'Accept': 'application/json',
+          'Content-Type': 'application/json',
         },
       },
     );