diff --git a/pkg/sessionctx/variable/session.go b/pkg/sessionctx/variable/session.go
index eec4abbdf73b9..2435ab8e7af8f 100644
--- a/pkg/sessionctx/variable/session.go
+++ b/pkg/sessionctx/variable/session.go
@@ -2606,6 +2606,8 @@ func (s *SessionVars) LazyCheckKeyNotExists() bool {
 // GetTemporaryTable returns a TempTable by tableInfo.
 func (s *SessionVars) GetTemporaryTable(tblInfo *model.TableInfo) tableutil.TempTable {
 	if tblInfo.TempTableType != model.TempTableNone {
+		s.TxnCtxMu.Lock()
+		defer s.TxnCtxMu.Unlock()
 		if s.TxnCtx.TemporaryTables == nil {
 			s.TxnCtx.TemporaryTables = make(map[int64]tableutil.TempTable)
 		}