diff --git a/framework/framework/api.ts b/framework/framework/api.ts
index 20cb73ede..c4910092b 100644
--- a/framework/framework/api.ts
+++ b/framework/framework/api.ts
@@ -126,7 +126,7 @@ export class ApiService extends Service {
             await emitHook?.(`api/before/${callOrName}`, args);
         }
         const result = await func(context, args as any);
-        return project ? projection(result, project) : result;
+        return (project && typeof result === 'object' && result !== null) ? projection(result, project) : result;
     }
 }
 
diff --git a/packages/hydrooj/src/upgrade.ts b/packages/hydrooj/src/upgrade.ts
index ee2c28489..6317423c2 100644
--- a/packages/hydrooj/src/upgrade.ts
+++ b/packages/hydrooj/src/upgrade.ts
@@ -609,7 +609,7 @@ export const coreScripts: MigrationScript[] = [
             const docs = await c.oauth.coll.find({ id: { $type: 'number' as any } }).toArray();
             const op = c.oauth.coll.initializeUnorderedBulkOp();
             for (const doc of docs) {
-                op.find({ _id: doc._id }).updateOne({ id: doc.id.toString() });
+                op.find({ _id: doc._id }).updateOne({ $set: { id: doc.id.toString() } });
             }
             if (op.length) await op.execute();
         });