diff --git a/ast/encode_test.go b/ast/encode_test.go
index bbcc709e3..a333b0688 100644
--- a/ast/encode_test.go
+++ b/ast/encode_test.go
@@ -169,15 +169,15 @@ func (j *SortableNode) MarshalJSON() ([]byte, error) {
 }
 
 func TestMarshalSort(t *testing.T) {
-    var data = `{"d":3,"a":{"c":1,"b":2}}`
+    var data = `{"d":3,"a":{"c":1,"b":2},"e":null}`
     var obj map[string]*SortableNode
     require.NoError(t, json.Unmarshal([]byte(data), &obj))
     out, err := json.Marshal(obj)
     require.NoError(t, err)
-    require.Equal(t, `{"a":{"b":2,"c":1},"d":3}`, string(out))
+    require.Equal(t, `{"a":{"b":2,"c":1},"d":3,"e":null}`, string(out))
     out, err = json.Marshal(obj)
     require.NoError(t, err)
-    require.Equal(t, `{"a":{"b":2,"c":1},"d":3}`, string(out))
+    require.Equal(t, `{"a":{"b":2,"c":1},"d":3,"e":null}`, string(out))
 }
 
 func BenchmarkEncodeRaw_Sonic(b *testing.B) {
diff --git a/ast/node.go b/ast/node.go
index b888684d7..990908ddd 100644
--- a/ast/node.go
+++ b/ast/node.go
@@ -844,6 +844,7 @@ func (self *Node) MapUseNode() (map[string]Node, error) {
 //     return self.toGenericObjectUsePair()
 // }
 
+//go:nocheckptr
 func (self *Node) unsafeMap() (*linkedPairs, error) {
     if err := self.skipAllKey(); err != nil {
         return nil, err
@@ -866,7 +867,7 @@ func (self *Node) SortKeys(recurse bool) error {
     } else {
         var err error
         err2 := self.ForEach(func(path Sequence, node *Node) bool {
-            it := self.itype()
+            it := node.itype()
             if it == types.V_ARRAY || it == types.V_OBJECT {
                 err = node.SortKeys(recurse)
                 if err != nil {