diff --git a/Frontend/src/components/MilestonesPanel.tsx b/Frontend/src/components/MilestonesPanel.tsx
index 6b2633c..f8c65d5 100644
--- a/Frontend/src/components/MilestonesPanel.tsx
+++ b/Frontend/src/components/MilestonesPanel.tsx
@@ -13,7 +13,8 @@ export function MilestonesPanel() {
 
   const claimable = getClaimableMilestones(state);
   const nextMilestone = getNextMilestone(state);
-  const totalClaimed = state.claimedMilestones.length;
+  const claimed = state.claimedMilestones ?? [];
+  const totalClaimed = claimed.length;
 
   return (
     <div className="gp">
@@ -73,7 +74,7 @@ export function MilestonesPanel() {
       {/* Liste compacte des milestones passés */}
       {totalClaimed > 0 && claimable.length === 0 && (
         <div className="flex flex-wrap gap-1 mt-1">
-          {PRESTIGE_MILESTONES.filter((m) => state.claimedMilestones.includes(m.id)).map((m) => (
+          {PRESTIGE_MILESTONES.filter((m) => claimed.includes(m.id)).map((m) => (
             <span
               key={m.id}
               className="gp-label text-[0.55rem]! px-1.5 py-0.5 rounded bg-purple-500/10 border border-purple-500/20"