diff --git a/apps/iris/src/common/constants/constants.go b/apps/iris/src/common/constants/constants.go
index 0aae1ce8cc..dccb337ead 100644
--- a/apps/iris/src/common/constants/constants.go
+++ b/apps/iris/src/common/constants/constants.go
@@ -53,3 +53,5 @@ const (
 	EXCHANGE   = "judger-exchange"
 	RESULT_KEY = "result"
 )
+
+const MAX_OUTPUT = 1048576 // 1MB
diff --git a/apps/iris/src/handler/judge-handler.go b/apps/iris/src/handler/judge-handler.go
index 547ca24afc..14241b1435 100644
--- a/apps/iris/src/handler/judge-handler.go
+++ b/apps/iris/src/handler/judge-handler.go
@@ -347,6 +347,10 @@ func (j *JudgeHandler) judgeTestcase(idx int, dir string, validReq *Request,
 	res.SetJudgeExecResult(runResult.ExecResult)
 	res.Output = string(runResult.Output)
 
+	if len(res.Output) > constants.MAX_OUTPUT {
+		res.Output = res.Output[:constants.MAX_OUTPUT]
+	}
+
 	if runResult.ExecResult.ResultCode != sandbox.RUN_SUCCESS {
 		res.SetJudgeResultCode(SandboxResultCodeToJudgeResultCode(runResult.ExecResult.ResultCode))
 		goto Send