diff --git a/packages/hydrooj/package.json b/packages/hydrooj/package.json
index 573080ce..b5f7c3d0 100644
--- a/packages/hydrooj/package.json
+++ b/packages/hydrooj/package.json
@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.28.6",
+    "version": "2.28.7",
     "bin": "bin/hydrooj.js",
     "main": "dist/loader.js",
     "typings": "dist/loader.d.ts",
diff --git a/packages/hydrooj/src/handler/homework.ts b/packages/hydrooj/src/handler/homework.ts
index f3659b8a..d0f760ad 100644
--- a/packages/hydrooj/src/handler/homework.ts
+++ b/packages/hydrooj/src/handler/homework.ts
@@ -283,8 +283,8 @@ class HomeworkEditHandler extends Handler {
             datePenaltyText: penaltySince.format('YYYY-M-D'),
             timePenaltyText: penaltySince.format('hh:mm'),
             extensionDays,
-            penaltyRules: yaml.dump(tdoc.penaltyRules),
-            pids: tdoc.pids.join(','),
+            penaltyRules: tid ? yaml.dump(tdoc.penaltyRules) : null,
+            pids: tid ? tdoc.pids.join(',') : '',
             path,
             page_name: tid ? 'homework_edit' : 'homework_create',
         };