diff --git a/internal/option.go b/internal/option.go
index 0539689..d10c091 100644
--- a/internal/option.go
+++ b/internal/option.go
@@ -505,7 +505,7 @@ func (opt *Option) PrepareRunner() (*Runner, error) {
 	logs.Log.Importantf("Loaded %d dictionaries and %d decorators", len(opt.Dictionaries), len(r.Fns))
 
 	if opt.Match != "" {
-		exp, err := expr.Compile(opt.Match)
+		exp, err := expr.Compile(opt.Match, expr.Patch(&bytesPatcher{}))
 		if err != nil {
 			return nil, err
 		}
@@ -513,7 +513,7 @@ func (opt *Option) PrepareRunner() (*Runner, error) {
 	}
 
 	if opt.Filter != "" {
-		exp, err := expr.Compile(opt.Filter)
+		exp, err := expr.Compile(opt.Filter, expr.Patch(&bytesPatcher{}))
 		if err != nil {
 			return nil, err
 		}
@@ -535,7 +535,7 @@ func (opt *Option) PrepareRunner() (*Runner, error) {
 	}
 
 	if express != "" {
-		exp, err := expr.Compile(express)
+		exp, err := expr.Compile(express, expr.Patch(&bytesPatcher{}))
 		if err != nil {
 			return nil, err
 		}
diff --git a/internal/utils.go b/internal/utils.go
index ca81894..2ff9073 100644
--- a/internal/utils.go
+++ b/internal/utils.go
@@ -3,6 +3,7 @@ package internal
 import (
 	"bytes"
 	"github.com/antonmedv/expr"
+	"github.com/antonmedv/expr/ast"
 	"github.com/antonmedv/expr/vm"
 	"github.com/chainreactors/logs"
 	"github.com/chainreactors/spray/pkg"
@@ -276,3 +277,18 @@ func MatchWithGlobs(u string, globs []string) bool {
 	}
 	return false
 }
+
+type bytesPatcher struct{}
+
+func (p *bytesPatcher) Visit(node *ast.Node) {
+	switch (*node).(type) {
+	case *ast.MemberNode:
+		ast.Patch(node, &ast.CallNode{
+			Callee: &ast.MemberNode{
+				Node:     *node,
+				Name:     "String",
+				Property: &ast.StringNode{Value: "String"},
+			},
+		})
+	}
+}
diff --git a/pkg/baseline.go b/pkg/baseline.go
index ebcb357..c015ba9 100644
--- a/pkg/baseline.go
+++ b/pkg/baseline.go
@@ -105,9 +105,9 @@ type Baseline struct {
 	Url       *url.URL `json:"-"`
 	Dir       bool     `json:"-"`
 	Chunked   bool     `json:"-"`
-	Body      []byte   `json:"-"`
-	Header    []byte   `json:"-"`
-	Raw       []byte   `json:"-"`
+	Body      BS       `json:"-"`
+	Header    BS       `json:"-"`
+	Raw       BS       `json:"-"`
 	Recu      bool     `json:"-"`
 	RecuDepth int      `json:"-"`
 	URLs      []string `json:"-"`
diff --git a/pkg/types.go b/pkg/types.go
index 1dd3575..a5012af 100644
--- a/pkg/types.go
+++ b/pkg/types.go
@@ -37,3 +37,9 @@ var ErrMap = map[ErrorType]string{
 func (e ErrorType) Error() string {
 	return ErrMap[e]
 }
+
+type BS []byte
+
+func (b BS) String() string {
+	return string(b)
+}