diff --git a/clone.go b/clone.go
index ba51fdf..c516afe 100644
--- a/clone.go
+++ b/clone.go
@@ -12,6 +12,13 @@ const (
 	maxDepth = 32
 )
 
+var (
+	// ignoreTypes is a map of types that should not be redacted. It lists types that can not be copied. For example, reflect.Type is a pointer to a struct and copying it causes panic. Especially, reflect.rtype is unexported type. Then, the ignoreTypes is list of string of type name.
+	ignoreTypes = map[string]struct{}{
+		"*reflect.rtype": {},
+	}
+)
+
 func (x *masq) clone(ctx context.Context, fieldName string, src reflect.Value, tag string) reflect.Value {
 	if v, ok := ctx.Value(ctxKeyDepth{}).(int); !ok {
 		ctx = context.WithValue(ctx, ctxKeyDepth{}, 0)
@@ -26,6 +33,9 @@ func (x *masq) clone(ctx context.Context, fieldName string, src reflect.Value, t
 	if _, ok := x.allowedTypes[src.Type()]; ok {
 		return src
 	}
+	if _, ok := ignoreTypes[src.Type().String()]; ok {
+		return src
+	}
 
 	if src.Kind() == reflect.Ptr && src.IsNil() {
 		return reflect.New(src.Type()).Elem()
@@ -58,7 +68,6 @@ func (x *masq) clone(ctx context.Context, fieldName string, src reflect.Value, t
 
 		for i := 0; i < t.NumField(); i++ {
 			f := t.Field(i)
-			println("f.Name", f.Name)
 			srcValue := src.Field(i)
 			dstValue := dst.Elem().Field(i)
 
@@ -83,10 +92,6 @@ func (x *masq) clone(ctx context.Context, fieldName string, src reflect.Value, t
 				}
 
 				srcValue = reflect.NewAt(srcValue.Type(), unsafe.Pointer(srcValue.UnsafeAddr())).Elem()
-			} else if srcValue.Kind() == reflect.Func {
-				println("func!")
-				dstValue.Set(srcValue)
-				continue
 			}
 
 			tagValue := f.Tag.Get(x.tagKey)
diff --git a/clone_test.go b/clone_test.go
index 7695a73..b83de00 100644
--- a/clone_test.go
+++ b/clone_test.go
@@ -344,16 +344,20 @@ func TestCircularReference(t *testing.T) {
 	gt.V(t, newData.Child.Child.Str).Equal("[REDACTED]")
 }
 
-func TestCloneJsonUnmarshalTypeError(t *testing.T) {
-	var s string
-	src := json.Unmarshal([]byte(`["foo"]`), &s).(*json.UnmarshalTypeError)
-	dst := masq.NewMasq().Redact(src).(*json.UnmarshalTypeError)
-	gt.Equal(t, dst, src)
-}
-
 func TestCloneFunc(t *testing.T) {
 	type myFunc func() string
 	src := myFunc(func() string { return "blue" })
 	dst := masq.NewMasq().Redact(src).(myFunc)
 	gt.Equal(t, dst(), "blue")
 }
+
+func TestUnmarshalTypeError(t *testing.T) {
+	var buf bytes.Buffer
+	logger := slog.New(slog.NewJSONHandler(&buf, &slog.HandlerOptions{
+		ReplaceAttr: masq.New(),
+	}))
+	var s string
+	err := json.Unmarshal([]byte(`["foo"]`), &s)
+	logger.Info("error", slog.Any("err", err))
+	gt.S(t, buf.String()).Contains("error")
+}
diff --git a/masq_test.go b/masq_test.go
index d3bbf3a..ab3f201 100644
--- a/masq_test.go
+++ b/masq_test.go
@@ -1,10 +1,7 @@
 package masq_test
 
 import (
-	"encoding/json"
 	"os"
-	"reflect"
-	"testing"
 
 	"log/slog"
 
@@ -28,19 +25,3 @@ func Example() {
 
 	logger.Info("hello", slog.Any("user", u))
 }
-
-func TestJsonUnmarshalTypeError(t *testing.T) {
-	// It should not panic
-	logger := slog.New(
-		slog.NewJSONHandler(
-			os.Stdout,
-			&slog.HandlerOptions{
-				ReplaceAttr: masq.New(masq.WithAllowedType(reflect.TypeOf(json.UnmarshalTypeError{}))),
-			},
-		),
-	)
-	var s string
-	err := json.Unmarshal([]byte(`["foo"]`), &s)
-	slog.Info("error", "err", err)
-	logger.Info("error", "err", err)
-}