diff --git a/resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/k8s/features/MountVolumesFeatureStep.scala b/resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/k8s/features/MountVolumesFeatureStep.scala
index fe4717d09951..788ddeaf51cb 100644
--- a/resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/k8s/features/MountVolumesFeatureStep.scala
+++ b/resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/k8s/features/MountVolumesFeatureStep.scala
@@ -114,7 +114,7 @@ private[spark] class MountVolumesFeatureStep(conf: KubernetesConf)
   }
 
   override def getAdditionalKubernetesResources(): Seq[HasMetadata] = {
-    additionalResources
+    additionalResources.toSeq
   }
 }