diff --git a/src/pages/MilestoneDetailPage.tsx b/src/pages/MilestoneDetailPage.tsx
index 4e92c31..96eebea 100644
--- a/src/pages/MilestoneDetailPage.tsx
+++ b/src/pages/MilestoneDetailPage.tsx
@@ -153,7 +153,12 @@ export default function MilestoneDetailPage() {
           {milestone.planned_release_date && <span className="text-dim">Planned Release: {dayjs(milestone.planned_release_date).format('YYYY-MM-DD')}</span>}
           {milestone.started_at && <span className="text-dim">Started: {dayjs(milestone.started_at).format('YYYY-MM-DD HH:mm')}</span>}
         </div>
-        {canEditMilestone && !isTerminal && <button className="btn-transition" style={{ marginTop: 8 }} onClick={() => setShowEditMilestone(true)}>Edit Milestone</button>}
+        {canEditMilestone && msStatus === 'open' && <button className="btn-transition" style={{ marginTop: 8 }} onClick={() => setShowEditMilestone(true)}>Edit Milestone</button>}
+        {canEditMilestone && (msStatus === 'freeze' || msStatus === 'undergoing') && (
+          <span className="text-dim" style={{ marginTop: 8, display: 'inline-block' }}>
+            ⚠ Milestone is {msStatus} — scope fields are locked
+          </span>
+        )}
 
         {/* Milestone status action buttons (P8.2) */}
         {!isTerminal && (