diff --git a/pkg/ddl/backfilling_dispatcher.go b/pkg/ddl/backfilling_dispatcher.go
index 4fd36bba20a1c..527e83190ca10 100644
--- a/pkg/ddl/backfilling_dispatcher.go
+++ b/pkg/ddl/backfilling_dispatcher.go
@@ -353,7 +353,7 @@ func (dsp *BackfillingDispatcherExt) generateNonPartitionPlan(
 	return subTaskMetas, nil
 }
 
-func (dsp *BackfillingDispatcherExt) getWriterMemSize(backfillMeta *BackfillGlobalMeta) (uint64, error) {
+func (*BackfillingDispatcherExt) getWriterMemSize(backfillMeta *BackfillGlobalMeta) (uint64, error) {
 	failpoint.Inject("mockWriterMemSize", func() {
 		failpoint.Return(1*size.GB, nil)
 	})