diff --git a/decoder/decoder_native_test.go b/decoder/decoder_native_test.go
index 45d326788..62e85b52a 100644
--- a/decoder/decoder_native_test.go
+++ b/decoder/decoder_native_test.go
@@ -81,7 +81,6 @@ func TestDecoder_OptionCaseSensitiveForManyKeys(t *testing.T) {
 
         var obj2 = TS{}
         d := NewDecoder(js)
-        // d.SetOptions(OptionCaseSensitive)
         err2 := d.Decode(&obj2)
         require.NoError(t, err2)
         require.Equal(t, obj, obj2)
diff --git a/internal/decoder/jitdec/assembler_regabi_amd64.go b/internal/decoder/jitdec/assembler_regabi_amd64.go
index 1ceb96b6c..29f6a4a84 100644
--- a/internal/decoder/jitdec/assembler_regabi_amd64.go
+++ b/internal/decoder/jitdec/assembler_regabi_amd64.go
@@ -1799,6 +1799,9 @@ func (self *_Assembler) _asm_OP_struct_field(p *_Instr) {
     self.Emit("TESTQ", _AX, _AX)                                // TESTQ   AX, AX
     self.Sjmp("JNS"  , "_end_{n}")                              // JNS     _end_{n}
     self.Link("_unknown_{n}")
+    // HACK: because `_VAR_sr` maybe used in `F_vstring`, so we should clear here again for `_OP_switch`.
+    self.Emit("MOVQ" , jit.Imm(-1), _AX)                        // MOVQ    $-1, AX
+    self.Emit("MOVQ" , _AX, _VAR_sr)                            // MOVQ    AX, sr
     self.Emit("BTQ"  , jit.Imm(_F_disable_unknown), _ARG_fv)    // BTQ     ${_F_disable_unknown}, fv
     self.Sjmp("JC"   , _LB_field_error)                         // JC      _field_error
     self.Link("_end_{n}")                                       // _end_{n}: