diff --git a/pkg/planner/core/plan_test.go b/pkg/planner/core/plan_test.go
index 4baa378a67..cbd923c474 100644
--- a/pkg/planner/core/plan_test.go
+++ b/pkg/planner/core/plan_test.go
@@ -713,8 +713,8 @@ func TestImportIntoBuildPlan(t *testing.T) {
 
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
-	tk.MustExec("create table t1 (a int, b int);")
-	tk.MustExec("create table t2 (a int, b int);")
+	tk.MustExec("create table t1 (a int, b int, c datetime on update CURRENT_TIMESTAMP);")
+	tk.MustExec("create table t2 (a int, b int, c datetime on update CURRENT_TIMESTAMP);")
 	require.ErrorIs(t, tk.ExecToErr("IMPORT INTO t1 FROM select a from t2;"),
 		plannererrors.ErrWrongValueCountOnRow)
 	require.ErrorIs(t, tk.ExecToErr("IMPORT INTO t1(a) FROM select * from t2;"),
diff --git a/pkg/planner/core/planbuilder.go b/pkg/planner/core/planbuilder.go
index ad7e07e7e7..0d9d7abb13 100644
--- a/pkg/planner/core/planbuilder.go
+++ b/pkg/planner/core/planbuilder.go
@@ -3994,13 +3994,12 @@ func (b *PlanBuilder) getDefaultValueForInsert(col *table.Column) (*expression.C
 }
 
 // resolveGeneratedColumns resolves generated columns with their generation expressions respectively.
-// onDups indicates which columns are in on-duplicate list
-// and it will be **modified** inside this function.
+// If not-nil onDups is passed in, it will be **modified in place** and record columns in on-duplicate list
 func (b *PlanBuilder) resolveGeneratedColumns(ctx context.Context, columns []*table.Column, onDups map[string]struct{}, mockPlan base.LogicalPlan) (igc InsertGeneratedColumns, err error) {
 	for _, column := range columns {
 		if !column.IsGenerated() {
 			// columns having on-update-now flag should also be considered.
-			if mysql.HasOnUpdateNowFlag(column.GetFlag()) {
+			if onDups != nil && mysql.HasOnUpdateNowFlag(column.GetFlag()) {
 				onDups[column.Name.L] = struct{}{}
 			}
 			continue
diff --git a/tests/realtikvtest/importintotest/import_into_test.go b/tests/realtikvtest/importintotest/import_into_test.go
index a9f2bd520a..43220f248d 100644
--- a/tests/realtikvtest/importintotest/import_into_test.go
+++ b/tests/realtikvtest/importintotest/import_into_test.go
@@ -331,6 +331,22 @@ func (s *mockGCSSuite) TestInputNull() {
 	s.tk.MustQuery("SELECT * FROM t;").Check(testkit.Rows([]string{"1 def 11", "2 test2 22"}...))
 }
 
+func (s *mockGCSSuite) TestOnUpdateColumn() {
+	s.server.CreateObject(fakestorage.Object{
+		ObjectAttrs: fakestorage.ObjectAttrs{
+			BucketName: "test-on-update",
+			Name:       "on-update.tsv",
+		},
+		Content: []byte("1,2025-08-22 02:35:00"),
+	})
+	s.prepareAndUseDB("load_data")
+	s.tk.MustExec("drop table if exists t;")
+	s.tk.MustExec("create table t(id int, c1 datetime on update CURRENT_TIMESTAMP)")
+	loadDataSQL := fmt.Sprintf(`IMPORT INTO t FROM 'gs://test-on-update/on-update.tsv?endpoint=%s'`, gcsEndpoint)
+	s.tk.MustQuery(loadDataSQL)
+	s.tk.MustQuery("SELECT * FROM t;").Check(testkit.Rows([]string{"1 2025-08-22 02:35:00"}...))
+}
+
 func (s *mockGCSSuite) TestIgnoreNLines() {
 	s.server.CreateObject(fakestorage.Object{
 		ObjectAttrs: fakestorage.ObjectAttrs{BucketName: "test-multi-load", Name: "skip-rows-1.csv"},