diff --git a/expression/column.go b/expression/column.go
index 02eab5c0314bb..f63cf44a117a5 100644
--- a/expression/column.go
+++ b/expression/column.go
@@ -377,7 +377,7 @@ func IndexInfo2Cols(cols []*Column, index *model.IndexInfo) ([]*Column, []int) {
 }
 
 // FindColumnsByUniqueIDs will find columns by checking the unique id.
-// Note: This id list must be a subset of the column slice.
+// Note: `ids` must be a subset of the column slice.
 func FindColumnsByUniqueIDs(cols []*Column, ids []int) []*Column {
 	retCols := make([]*Column, 0, len(ids))
 	for _, id := range ids {
diff --git a/plan/logical_plans_test.go b/plan/logical_plans_test.go
index 709576db82ade..6ec6894d51381 100644
--- a/plan/logical_plans_test.go
+++ b/plan/logical_plans_test.go
@@ -54,8 +54,8 @@ func (s *testUnitTestSuit) SubstituteCol2CorCol(expr expression.Expression, colI
 			}
 			newArgs = append(newArgs, newArg)
 		}
-		newSf := expression.NewFunctionInternal(x.GetCtx(), x.FuncName.L, x.GetType(), newArgs...)
-		return newSf, nil
+		newSf, err := expression.NewFunction(x.GetCtx(), x.FuncName.L, x.GetType(), newArgs...)
+		return newSf, errors.Trace(err)
 	case *expression.Column:
 		if _, ok := colIDs[x.UniqueID]; ok {
 			return &expression.CorrelatedColumn{Column: *x}, nil