diff --git a/packages/hydrojudge/package.json b/packages/hydrojudge/package.json
index dea22e6fd..c00979bab 100644
--- a/packages/hydrojudge/package.json
+++ b/packages/hydrojudge/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@hydrooj/hydrojudge",
     "bin": "bin/hydrojudge.js",
-    "version": "2.5.5",
+    "version": "2.5.6",
     "main": "package.json",
     "author": "undefined <i@undefined.moe>",
     "repository": "https://github.com/hydro-dev/Hydro.git",
diff --git a/packages/hydrojudge/src/sandbox.ts b/packages/hydrojudge/src/sandbox.ts
index 405dbb3ba..6c066adaf 100644
--- a/packages/hydrojudge/src/sandbox.ts
+++ b/packages/hydrojudge/src/sandbox.ts
@@ -98,6 +98,7 @@ export async function runMultiple(execute) {
         res = await axios.post('/run', body);
         if (argv['show-sandbox-call']) logger.debug('%d %s', id, JSON.stringify(res.data));
     } catch (e) {
+        if (e instanceof FormatError) throw e;
         throw new SystemError('Sandbox Error');
     }
     return await Promise.all(res.data.map((i) => adaptResult(i, {})));
@@ -121,6 +122,7 @@ export async function run(execute, params?) {
         if (argv['show-sandbox-call']) logger.debug('%d %s', id, JSON.stringify(res.data));
         [result] = res.data;
     } catch (e) {
+        if (e instanceof FormatError) throw e;
         // FIXME request body larger than maxBodyLength limit
         throw new SystemError('Sandbox Error', e.message);
     }