diff --git a/packages/hydrooj/src/handler/home.ts b/packages/hydrooj/src/handler/home.ts
index ba773d86..28f99a6e 100644
--- a/packages/hydrooj/src/handler/home.ts
+++ b/packages/hydrooj/src/handler/home.ts
@@ -441,7 +441,7 @@ class HomeDomainHandler extends Handler {
 
     @param('id', Types.String)
     async postStar(domainId: string, id: string) {
-        await user.setById(this.user._id, { pinnedDomains: this.user.pinnedDomains.concat(id) });
+        await user.setById(this.user._id, { pinnedDomains: [...this.user.pinnedDomains, id] });
         this.back({ star: true });
     }
 
@@ -470,7 +470,7 @@ class HomeDomainCreateHandler extends Handler {
         await Promise.all([
             domain.edit(domainId, { avatar }),
             domain.setUserRole(domainId, this.user._id, 'root'),
-            user.setById(this.user._id, undefined, undefined, { pinnedDomains: [domainId] }),
+            user.setById(this.user._id, undefined, undefined, { pinnedDomains: domainId }),
         ]);
         this.response.redirect = this.url('domain_dashboard', { domainId });
         this.response.body = { domainId };
diff --git a/packages/hydrooj/src/upgrade.ts b/packages/hydrooj/src/upgrade.ts
index 59f00f6f..93a48214 100644
--- a/packages/hydrooj/src/upgrade.ts
+++ b/packages/hydrooj/src/upgrade.ts
@@ -587,6 +587,16 @@ const scripts: UpgradeScript[] = [
         await document.coll.updateMany({ docType: document.TYPE_TRAINING, pin: true }, { $set: { pin: 1 } });
         return true;
     },
+    async function _81_82() {
+        return await iterateAllUser((udoc) => {
+            let pinnedDomains = new Set<string>();
+            for (const d of udoc.pinnedDomains) {
+                if (typeof d === 'string') pinnedDomains.add(d);
+                else pinnedDomains = Set.union(pinnedDomains, d);
+            }
+            return user.setById(udoc._id, { pinnedDomains: Array.from(pinnedDomains) });
+        });
+    },
 ];
 
 export default scripts;