diff --git a/packages/hydrooj/package.json b/packages/hydrooj/package.json
index 2f14f738..99991e5e 100644
--- a/packages/hydrooj/package.json
+++ b/packages/hydrooj/package.json
@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.20.47",
+    "version": "2.20.48",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",
diff --git a/packages/hydrooj/src/upgrade.ts b/packages/hydrooj/src/upgrade.ts
index 2d812512..0e29408e 100644
--- a/packages/hydrooj/src/upgrade.ts
+++ b/packages/hydrooj/src/upgrade.ts
@@ -236,9 +236,9 @@ const scripts: UpgradeScript[] = [
         const _FRESH_INSTALL_IGNORE = 1;
         await iterateAllProblem(['data', 'additional_file'], async (pdoc) => {
             const $set: any = {};
-            const td = pdoc.data.filter((f) => f.name);
+            const td = (pdoc.data || []).filter((f) => !!f.name);
             if (JSON.stringify(td) !== JSON.stringify(pdoc.data)) $set.data = td;
-            const af = pdoc.additional_file.filter((f) => f.name);
+            const af = (pdoc.additional_file || []).filter((f) => !!f.name);
             if (JSON.stringify(af) !== JSON.stringify(pdoc.additional_file)) $set.additional_file = af;
             if (Object.keys($set).length) await problem.edit(pdoc.domainId, pdoc.docId, $set);
         });