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
@@ -65,6 +65,7 @@
   MinimallyEncodedThreadCurrentUserInfo,
   MinimallyEncodedThreadInfo,
 } from '../types/minimally-encoded-thread-permissions-types.js';
+import { decodeMinimallyEncodedRoleInfo } from '../types/minimally-encoded-thread-permissions-types.js';
 import { userRelationshipStatus } from '../types/relationship-types.js';
 import {
   threadPermissionPropagationPrefixes,
@@ -1480,7 +1481,9 @@
   return !!messageItem.threadCreatedFromMessage || canCreateSidebarFromMessage;
 }
 
-function checkIfDefaultMembersAreVoiced(threadInfo: ThreadInfo): boolean {
+function checkIfDefaultMembersAreVoiced(
+  threadInfo: ThreadInfo | MinimallyEncodedThreadInfo,
+): boolean {
   const defaultRoleID = Object.keys(threadInfo.roles).find(
     roleID => threadInfo.roles[roleID].isDefault,
   );
@@ -1489,7 +1492,11 @@
     'all threads should have a default role',
   );
   const defaultRole = threadInfo.roles[defaultRoleID];
-  return !!defaultRole.permissions[threadPermissions.VOICED];
+  const defaultRolePermissions = defaultRole.minimallyEncoded
+    ? decodeMinimallyEncodedRoleInfo(defaultRole).permissions
+    : defaultRole.permissions;
+
+  return !!defaultRolePermissions[threadPermissions.VOICED];
 }
 
 const draftKeySuffix = '/message_composer';