diff --git a/go/vt/vttablet/onlineddl/executor.go b/go/vt/vttablet/onlineddl/executor.go
index 2f4466936fb..d95d4afc41f 100644
--- a/go/vt/vttablet/onlineddl/executor.go
+++ b/go/vt/vttablet/onlineddl/executor.go
@@ -4635,6 +4635,7 @@ func (e *Executor) SubmitMigration(
 	revertedUUID, _ := onlineDDL.GetRevertUUID() // Empty value if the migration is not actually a REVERT. Safe to ignore error.
 	retainArtifactsSeconds := int64((retainOnlineDDLTables).Seconds())
 	if retainArtifacts, _ := onlineDDL.StrategySetting().RetainArtifactsDuration(); retainArtifacts != 0 {
+		// Explicit retention indicated by `--retain-artifact` DDL strategy flag for this migration. Override!
 		retainArtifactsSeconds = int64((retainArtifacts).Seconds())
 	}