diff --git a/pkg/controller/deployment/sync.go b/pkg/controller/deployment/sync.go
index a92904dd3d5..b0a6e7e3f14 100644
--- a/pkg/controller/deployment/sync.go
+++ b/pkg/controller/deployment/sync.go
@@ -125,6 +125,7 @@ func (dc *DeploymentController) getAllReplicaSetsAndSyncRevision(d *apps.Deploym
 }
 
 const (
+	// limit revision history length to 100 element (~2000 chars)
 	maxRevHistoryLengthInChars = 2000
 )