diff --git a/lib/shared/thread-utils.js b/lib/shared/thread-utils.js
--- a/lib/shared/thread-utils.js
+++ b/lib/shared/thread-utils.js
@@ -845,6 +845,11 @@
     permissions: filterThreadPermissions(role.permissions),
   }))(serverThreadInfo.roles);
 
+  const rolesWithoutSpecialRoleField = _mapValues(role => {
+    const { specialRole, ...roleSansSpecialRole } = role;
+    return roleSansSpecialRole;
+  })(rolesWithFilteredThreadPermissions);
+
   let rawThreadInfo: any = {
     id: serverThreadInfo.id,
     type: serverThreadInfo.type,
@@ -854,7 +859,7 @@
     creationTime: serverThreadInfo.creationTime,
     parentThreadID: serverThreadInfo.parentThreadID,
     members,
-    roles: rolesWithFilteredThreadPermissions,
+    roles: rolesWithoutSpecialRoleField,
     currentUser,
     repliesCount: serverThreadInfo.repliesCount,
     containingThreadID: serverThreadInfo.containingThreadID,