diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d63b62184..c79a14cba 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -50,6 +50,7 @@ jobs:
         yarn set version stable
         yarn
         yarn dedupe
+        node build/prepare.js
       env:
         LICENSE_KEY: ${{ secrets.MAXMIND_KEY }}
     - name: Get specific changed files
diff --git a/packages/hydrooj/src/handler/problem.ts b/packages/hydrooj/src/handler/problem.ts
index 8adc71bcc..6f247de37 100644
--- a/packages/hydrooj/src/handler/problem.ts
+++ b/packages/hydrooj/src/handler/problem.ts
@@ -418,7 +418,8 @@ export class ProblemDetailHandler extends ContestDetailBaseHandler {
                 contest.getRelated(this.args.domainId, this.pdoc.docId),
                 contest.getRelated(this.args.domainId, this.pdoc.docId, 'homework'),
             ])).map((tdocs) => tdocs.filter((tdoc) =>
-                this.user.hasPerm(PERM.PERM_VIEW_HIDDEN_CONTEST) || !tdoc.assign?.length || new Set(tdoc.assign).intersection(new Set(this.user.group)).size,
+                this.user.hasPerm(PERM.PERM_VIEW_HIDDEN_CONTEST) || !tdoc.assign?.length
+                || new Set(tdoc.assign).intersection(new Set(this.user.group)).size,
             ));
         }
     }
diff --git a/packages/hydrooj/src/upgrade.ts b/packages/hydrooj/src/upgrade.ts
index 72d51edee..cebbddbf6 100644
--- a/packages/hydrooj/src/upgrade.ts
+++ b/packages/hydrooj/src/upgrade.ts
@@ -431,7 +431,7 @@ export const coreScripts: MigrationScript[] = [
             let pinnedDomains = new Set<string>();
             for (const d of udoc.pinnedDomains) {
                 if (typeof d === 'string') pinnedDomains.add(d);
-                else pinnedDomains = Set.union(pinnedDomains, d);
+                else pinnedDomains = pinnedDomains.union(new Set(d));
             }
             await user.setById(udoc._id, { pinnedDomains: Array.from(pinnedDomains) });
         });
diff --git a/packages/ui-default/pages/home_messages.page.tsx b/packages/ui-default/pages/home_messages.page.tsx
index 86bbfd4c1..7e2876d8c 100644
--- a/packages/ui-default/pages/home_messages.page.tsx
+++ b/packages/ui-default/pages/home_messages.page.tsx
@@ -58,7 +58,7 @@ const page = new NamedPage('home_messages', () => {
         credential: document.cookie.split('sid=')[1].split(';')[0],
         channels: ['message'],
       }));
-    }
+    };
     sock.onmessage = (message) => {
       const msg = JSON.parse(message.data);
       if (msg.operation !== 'event') return;